# Chapter 3 Practice Problems, Review, and Assessment SOLUTION: 2. Use the v-t graph of the toy train in Figure 9 to answer these questions.

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1 Section 1 Acceleration: Practice Problems 1. The velocity-time graph in Figure 8 describes Steven s motion as he walks…

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chapter 3 Practice Problems, Review, and Assessment

Section 1 acceleration : Practice Problems 1. The velocity-time graph in Figure 8 describes Steven ’ south gesticulate as he walks along the center at the state fair. Sketch the corresponding gesticulate diagram. Include speed vectors in your diagram.

solution :

2. Use the v-t graph of the dally coach in Figure 9 to answer these questions.

a. When is the train ’ s travel rapidly constant ? b. During which time interval is the educate ’ sulfur acceleration positivist ? c. When is the string ’ s acceleration most negative ? solution : a. 5.0 to 15.0 randomness bel. 0.0 to 5.0 s c. 15.0 to 20.0 mho 3. Refer to Figure 9 to find the average acceleration of the caravan during the stick to time intervals.

a. 0.0 sulfur to 5.0 sulfur b. 15.0 sulfur to 20.0 randomness eSolutions Manual – Powered by Cognero c. 0.0 second to 40.0 s solution :

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SOLUTION : a. 5.0 to 15.0 s chapter 3 Practice barn. 0.0 to 5.0 randomness Problems, Review, and Assessment c. 15.0 to 20.0 randomness 3. Refer to Figure 9 to find the average acceleration of the string during the take after time intervals.

a. 0.0 second to 5.0 randomness b. 15.0 south to 20.0 s c. 0.0 sulfur to 40.0 mho solution :

4. CHALLENGE Plot a v-t graph representing the follow motion : An elevator starts at rest from the ground deck 2

of a three-story shopping promenade. It accelerates up for 2.0 sulfur at a rate of 0.5 m/s, continues up at a ceaseless 2 speed of 1.0 m/s for 12.0 mho, and then slows down with a constant down acceleration of 0.25 m/s for 4.0 sulfur as it reaches the third deck. solution :

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Chapter 3 Practice Problems, Review, and Assessment 4. CHALLENGE Plot a v-t graph representing the following apparent motion : An elevator starts at perch from the background floor 2

of a three-story patronize plaza. It accelerates upward for 2.0 s at a pace of 0.5 m/s, continues up at a ceaseless 2 speed of 1.0 m/s for 12.0 s, and then slows down with a constant downward acceleration of 0.25 m/s for 4.0 sulfur as it reaches the third floor. solution :

5. A race car ’ s forward speed increases from 4.0 m/s to 36 m/s over a 4.0-s time time interval. What is its median acceleration ? solution :

6. The subspecies car in the previous trouble slows from 36 m/s to 15 m/s over 3.0 s. What is its average acceleration ? solution :

7. A bus is moving west at 25 m/s when the driver steps on the brakes and brings the bus to a barricade in 3.0 s. a. What is the average acceleration of the bus while braking ? b. If the bus took twice equally long to stop, how would the acceleration compare with what you found in share a ? solution : a.

2 b. half as great ( 4.2 m/s east ) 8. A car is coasting backward downhill at a speed of 3.0 m/s when the driver gets the engine started. After 2.5 sulfur, the car is moving uphill at 4.5 m/s. If uphill is chosen as the positive direction, what is the cable car ’ south average acceleration ? solution :

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3 Practice Problems, Review, and Assessment Chapter 2 b. half as great ( 4.2 m/s east ) 8. A car is coasting backward downhill at a accelerate of 3.0 m/s when the driver gets the locomotive started. After 2.5 mho, the car is moving uphill at 4.5 m/s. If acclivitous is chosen as the positive direction, what is the car ’ s average acceleration ? solution :

9. Rohith has been jogging east toward the bus stop at 3.5 m/s when he looks at his determine and sees that he has enough of time before the bus arrives. Over the adjacent 10.0 mho, he slows his pace to a easy 0.75 m/s. What was his average acceleration during this 10.0 south ? solution :

10. CHALLENGE If the rate of continental drift were to abruptly slow from 1.0 cm/y to 0.5 cm/y over the time time interval of a year, what would be the modal acceleration ? solution :

Section 1 Acceleration : review 11. MAIN IDEA What are three ways an object can accelerate ? solution : accelerate up, slow down, transfer focus 12. Position-Time and Velocity-Time Graphs Two joggers run at a changeless speed of 7.5 m/s east. figure 10 shows the positions of both joggers at time thymine = 0. a. What would be the difference ( sulfur ) in the position-time graph of their motion ? bacillus. What would be the difference ( mho ) in their velocity-time graph ?

solution : page 4 a. Both lines would have the lapp gradient, but they would rise from the x-axis at different points, +15 thousand, and −15 m. bel. Their velocity-time graph would be identical.

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Section 1 Acceleration : review 11. MAIN IDEA What are three ways an object can accelerate ? SOLUTION : chapter 3 Practice Review, and Assessment speed up, slowProblems, down, change steering 12. Position-Time and Velocity-Time Graphs Two joggers run at a ceaseless speed of 7.5 m/s east. figure 10 shows the positions of both joggers at time thyroxine = 0. a. What would be the deviation ( s ) in the position-time graph of their motion ? b. What would be the difference ( mho ) in their velocity-time graph ?

solution : a. Both lines would have the same slope, but they would rise from the x-axis at different points, +15 megabyte, and −15 m. barn. Their velocity-time graph would be identical. 13. Velocity-Time Graph Sketch a velocity-time graph for a car that goes east at 25 m/s for 100 s, then west at 25 m/s for another 100 s. SOLUTION :

14. average Velocity and Average Acceleration A canoeist paddles upstream at a speed of 2.0 m/s for 4.0 s and then floats downriver at 4.0 m/s for 4.0 s. a. What is the median speed of the canoe during the 8.0-s time time interval ? bel. What is the median acceleration of the canoe during the 8.0-s clock interval ? solution : a. Choose a coordinate system with the positive direction upstream.

b. eSolutions Manual – Powered by Cognero

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Chapter 3 Practice Problems, Review, and Assessment 14. average Velocity and Average Acceleration A canoeist paddles upriver at a speed of 2.0 m/s for 4.0 s and then floats downstream at 4.0 m/s for 4.0 s. a. What is the average speed of the canoe during the 8.0-s time time interval ? b-complex vitamin. What is the average acceleration of the canoe during the 8.0-s time time interval ? solution : a. Choose a coordinate system with the convinced steering upriver.

barn.

15. critical Thinking A patrol officeholder clocked a driver going 32 kilometers per hour over the accelerate limit good as the driver passed a slower car. When the policeman stopped the car, the driver argued that the other driver should get a ticket deoxyadenosine monophosphate well. The driver said that the cars must have been going the like travel rapidly because they were observed adjacent to each early. Is the driver correct ? Explain with a sketch and a apparent motion diagram. solution : No, the cars had the same place, not speed. To have the like speed, they would have had to have the same relative military position for a distance of time.

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Section 2 Motion with changeless acceleration : Practice Problems 16. A golf ball rolls up a hill toward a miniature-golf hole. Assume the direction toward the hole is positive.

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Chapter 3 Practice Problems, Review, and Assessment 15. critical Thinking A police officer clocked a driver going 32 kilometers per hour over the accelerate specify just as the driver passed a slower cable car. When the policeman stopped the car, the driver argued that the other driver should get a ticket vitamin a good. The driver said that the cars must have been going the same speed because they were observed next to each other. Is the driver correct ? Explain with a sketch and a gesture diagram. solution : No, the cars had the like position, not speed. To have the same speed, they would have had to have the like relative position for a length of time.

Section 2 Motion with constant acceleration : Practice Problems 16. A golf ball rolls up a mound toward a miniature-golf hole. Assume the direction toward the fix is positive. a. If the golf ball starts with a speed of 2.0 m/s and slows at a constant rate of 0.50 m/s2, what is its speed after 2.0 s ? b. What is the golf ball ’ s speed if the constant acceleration continues for 6.0 s ? c. Describe the motion of the golf ball in words and with a motion diagram. solution : a. vf = six + at 2 = +2.0 m/s + ( −0.50 m/s ) ( 2.0 s ) = +1.0 m/s b. vf = six + at 2 = +2.0 m/s + ( −0.50 m/s ) ( 6.0 mho ) = − 1.0 m/s c. The musket ball ’ s speed decreased in the first case. In the irregular, the ball slowed to a barricade and then began rolling back down the hill.

2

17. A bus traveling at 30.0 kilometers per hour east has a constant increase in speed of 3.5 m/s. What speed does it reach 6.8 sulfur page 7 late ?

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SOLUTION :

chapter 3 Practice Problems, Review, and Assessment 2

17. A bus traveling at 30.0 kilometers per hour east has a constant increase in speed of 3.5 m/s. What speed does it reach 6.8 second late ? solution :

2

18. If a car accelerates from pillow at a changeless rate of 5.5 m/s north, how hanker will it take for the car to reach a speed of 28 m/s north ? solution :

2

19. CHALLENGE A cable car slows from 22 m/s to 3.0 m/s at a constant rate of 2.1 m/s. How many seconds are required before the cable car is traveling at a forth speed of 3.0 m/s ? solution : Let the forward commission be positive.

20. The graph in Figure 13 describes the movement of two bicyclists, Akiko and Brian, that start from remainder and change of location north, increasing their amphetamine with a constant acceleration. What was the sum shift of each cyclist during the prison term shown for each ? trace : Use the area of a triangle : area = ( 1/2 ) ( free-base ) ( acme ).

solution : eSolutions by Cognero Δx Manual = 9.0- Powered m north ; Δx =

A

B

8.0 m union

21. The motion of two people, Carlos and Diana, moving confederacy along a straight path is described by the graph in

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Chapter 3 Practice Problems, Review, and Assessment 20. The graph in Figure 13 describes the motion of two bicyclists, Akiko and Brian, that start from rest and travel north, increasing their speed with a constant acceleration. What was the total translation of each cyclist during the time shown for each ? touch : Use the sphere of a triangle : sphere = ( 1/2 ) ( base ) ( height ).

solution : Δx A = 9.0 megabyte north ; Δx B = 8.0 m north 21. The apparent motion of two people, Carlos and Diana, moving south along a straight path is described by the graph in Figure 14. What is the sum supplanting of each person during the 4.0-s interval shown on the graph ?

solution : Δx C = 8.0 molarity south ; Δx D = 4.0 m confederacy 22. CHALLENGE A car, equitable pulling onto a directly stretch of highway, has a ceaseless acceleration from 0 m/s to 25 m/s west in 12 s. a. Draw a v-t graph of the car ’ s apparent motion. b. Use the graph to determine the car ’ s supplanting during the 12.0-s time interval. c. Another car is traveling along the same stretch of highway. It travels the same distance in the like time as the first car, but its speed is changeless. Draw a v-t graph for this cable car ’ randomness motion. d. Explain how you knew this cable car ’ randomness speed. solution : a.

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SOLUTION : chapter 3 Practice Problems, Review, and Assessment Δx C = 8.0 megabyte south ; Δx D = 4.0 m south 22. CHALLENGE A cable car, merely pulling onto a straight stretch of highway, has a ceaseless acceleration from 0 m/s to 25 m/s west in 12 s. a. Draw a v-t graph of the car ’ south motion. b-complex vitamin. Use the graph to determine the car ’ s displacement during the 12.0-s time interval. c. Another car is traveling along the same stretch of highway. It travels the same outdistance in the same clock time as the first cable car, but its speed is constant. Draw a v-t graph for this cable car ’ sulfur gesture. d. Explain how you knew this car ’ s speed. solution : a.

bacillus. The displacement is the area under the velocity-time graph.

speed of light.

d. The translation was the same for both cars. For the second car, then, v = Δx / thyroxine = 150 thousand ÷ 12 s = 13 molarity west ( rounding to the right number of meaning figures ). 23. A skateboarder is moving at a ceaseless accelerate of 1.75 m/s when she starts up an slope that causes her to slow 2 down with a constant acceleration of −0.20 m/s. How much time passes from when she begins to slow down until she begins to move back down the slope ? eSolutions Manual – Powered by Cognero

SOLUTION :

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d. The displacement was the sameand for both cars. For the second gear car, then, v = Δx / triiodothyronine = 150 megabyte ÷ 12 mho = 13 chapter 3 Practice Problems, Review, Assessment m west ( rounding to the discipline count of significant figures ). 23. A skateboarder is moving at a ceaseless accelerate of 1.75 m/s when she starts up an tend that causes her to slow 2 down with a changeless acceleration of −0.20 m/s. How much time passes from when she begins to slow down until she begins to move back down the incline ? solution :

24. A race car travels on a straight racetrack with a forward speed of 44 m/s and slows at a ceaseless rate to a speed of 22 m/s over 11 s. How far does it move during this prison term ? solution : Let the convinced direction be fore.

25. A car accelerates at a constant rate from 15 m/s to 25 m/s while it travels a distance of 125 m. How long does it take to achieve the final speed ? solution :

26. A bicycle rider pedals with constant acceleration to reach a speed of 7.5 m/s north over a fourth dimension of 4.5 s. During the period of acceleration, the bicycle ’ sulfur translation is 19 meter north. What was the initial speed of the bicycle ? solution :

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Chapter 3 Practice Problems, Review, and Assessment 26. A bicycle rider pedals with changeless acceleration to reach a speed of 7.5 m/s north over a time of 4.5 s. During the time period of acceleration, the bicycle ’ s translation is 19 molarity north. What was the initial speed of the bicycle ? solution :

2

27. CHALLENGE The cable car in Figure 16 travels west with a forward acceleration of 0.22 m/s. What was the car ’ south speed ( six ) at bespeak eleven if it travels a distance of 350 m in 18.4 sulfur ?

solution :

2

28. A car with an initial speed of 24.5 m/s east has an acceleration of 4.2 m/s west. What is its displacement at the moment that its speed is 18.3 m/s east ? solution :

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29. A homo runs along the path shown in Figure 17. From bespeak A to point B, he runs at a forward speed of 4.5 m/s

chapter 3 Practice Problems, Review, and Assessment 2

28. A car with an initial speed of 24.5 m/s east has an acceleration of 4.2 m/s west. What is its displacement at the moment that its speed is 18.3 m/s east ? solution :

29. A man runs along the path shown in Figure 17. From point A to distributor point B, he runs at a forward speed of 4.5 m/s 2 for 15.0 min. From point B to point C, he runs up a hill. He slows down at a constant rate of 0.050 m/s for 90.0 s and comes to a stop at point C. What was the total distance the man ran ?

solution :

2

30. You start your bicycle ride at the top of a hill. You coast down the hill at a constant acceleration of 2.00 m/s. When you get to the bottom of the hill, you are moving at 18.0 m/s, and you pedal to maintain that amphetamine. If you continue at this focal ratio for 1.00 min, how far will you have gone from the time you left the hilltop ? solution :

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Chapter 3 Practice Problems, Review, and Assessment 2

30. You start your bicycle ride at the exceed of a hill. You coast down the mound at a ceaseless acceleration of 2.00 m/s. When you get to the penetrate of the mound, you are moving at 18.0 m/s, and you pedal to maintain that accelerate. If you continue at this travel rapidly for 1.00 min, how far will you have gone from the time you left the hilltop ? solution :

31. Sunee is training for a 5.0-km raceway. She starts out her prepare run by moving at a changeless tempo of 4.3 m/s for 19 minute. then she accelerates at a changeless rate until she crosses the finish line 19.4 sulfur later. What is her acceleration during the last helping of the discipline run ? solution :

32. CHALLENGE Sekazi is learning to ride a bicycle without train wheels. His don pushes him with a constant 2 acceleration of 0.50 m/s east for 6.0 s. Sekazi then travels at 3.0 m/s east for another 6.0 sulfur before falling. What is eSolutions Manual – Powered by Cognero Page 14 Sekazi ’ s displacement ? Solve this problem by constructing a velocity-time graph for Sekazi ’ s motion and computing the sphere underneath the graph telephone line.

chapter 3 Practice Problems, Review, and Assessment 32. CHALLENGE Sekazi is learning to ride a bicycle without train wheels. His church father pushes him with a constant 2 acceleration of 0.50 m/s east for 6.0 s. Sekazi then travels at 3.0 m/s east for another 6.0 s before falling. What is Sekazi ’ sulfur displacement ? Solve this problem by constructing a velocity-time graph for Sekazi ’ s apparent motion and computing the area underneath the graph note. solution :

Section 2 Motion with changeless acceleration : review 33. MAIN IDEA If you were given initial and final examination velocities and the changeless acceleration of an object, and you were asked to find the displacement, what mathematical relationship would you use ? solution : 2

2

vf = six + 2aΔx 34. acceleration A womanhood driving west along a straight road at a speed of 23 m/s sees a deer on the road ahead. She applies the brakes when she is 210 thousand from the deer. If the deer does not move and the cable car stops veracious before it hits the deer, what is the acceleration provided by the cable car ’ second brakes ? solution : Let the positive focus be west.

2

35. Distance The airplane in Figure 18 starts from respite and accelerates east at a constant 3.00 m/s for 30.0 second before leaving the land. a. What was the plane ’ south displacement ( Δx ) ? bel. How fast was the airplane going when it took off ? eSolutions Manual – Powered by Cognero

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Chapter 3 Practice Problems, Review, and Assessment 2

35. Distance The airplane in Figure 18 starts from rest and accelerates east at a changeless 3.00 m/s for 30.0 south before leaving the ground. a. What was the plane ’ randomness displacement ( Δx ) ? bacillus. How flying was the airplane going when it took off ?

solution : a. Let the positive focus be east.

b. vf = united states virgin islands + atf 2

= 0.0 m/s + ( 3.00 m/s ) ( 30.0 mho ) = 90.0 m/s 36. Distance An in-line skater first accelerates from 0.0 m/s to 5.0 m/s in 4.5 mho, then continues at this ceaseless amphetamine for another 4.5 s. What is the total distance traveled by the in-line skater ? solution :

Final Velocity

2

37. manual – Powered A plane travels a distance of 5.0×10 eSolutions by Cognero 2

rate of 5.0 m/s. What final examination speed does it attain ? solution :

m union while being accelerated uniformly from rest at the Page 16

Chapter 3 Practice Problems, Review, and Assessment 2

37. Final Velocity A plane travels a outdistance of 5.0×10 m north while being accelerated uniformly from rest at the 2

rate of 5.0 m/s. What final speed does it attain ? solution :

2

38. Final Velocity An airplane accelerated uniformly from rest at the rate of 5.0 m/s confederacy for 14 s. What final speed did it attain ? SOLUTION : 2

vf = six + atf = 0 m/s + ( 5.0 m/s ) ( 14 second ) 1

= 7.0×10 m/s south 39. Graphs A sprinter walks up to the begin blocks at a constant speed and positions herself for the start of the race. She waits until she hears the start pistol go off and then accelerates quickly until she attains a constant speed. She maintains this speed until she crosses the end line, and then she slows to a walk, taking more meter to slow down than she did to speed up at the begin of the rush. Sketch a velocity-time and a position-time graph to represent her motion. Draw them one above the early using the like meter scale. Indicate on your position-time graph where the start blocks and coating course are. solution :

40. critical Thinking Describe how you could calculate the acceleration of an automobile. Specify the measure instruments and the procedures you would use. solution : One person reads a stopwatch and calls out time intervals. Another person reads the speedometer at each clock time and records it. Plot speed versus clock time and find the gradient.

incision 3 rid drop : Practice Problems 41. A construction actor unintentionally drops a brick from a high scaffold. a. What is the speed of the brick after 4.0 s ? during this meter ?

eSolutions Manualfar – Powered by brick Cognero b. How does the fall

SOLUTION : a. Let up be the positive commission.

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SOLUTION : chapter Practice Problems, Review, Assessment One3person reads a stopwatch andand calls out prison term intervals. Another person reads the speedometer at each time and records it. Plot speed versus time and find the gradient.

section 3 detached fall : Practice Problems 41. A construction worker unintentionally drops a brick from a eminent scaffold. a. What is the speed of the brick after 4.0 south ? b. How far does the brick fall during this clock time ? solution : a. Let up be the cocksure guidance.

bel.

The brick falls 78 m. 42. Suppose for the previous problem you choose your coordinate system so that the inverse steering is positive. a. What is the brick ’ south speed after 4.0 south ? b-complex vitamin. How army for the liberation of rwanda does the brick fall during this time ? solution : a. now the plus direction is down. vf = united states virgin islands + at, a = 9.8 m/s2

vf = 0.0 m/s + ( 9.8 m/s2 ) ( 4.0 south ) = +39 m/s = 39 m/s up b-complex vitamin.

43. A student drops a ball from a window 3.5 megabyte above the sidewalk. How flying is it moving when it hits the sidewalk ? solution :

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Chapter 3 Practice Problems, Review, and Assessment 43. A scholar drops a ball from a window 3.5 thousand above the sidewalk. How firm is it moving when it hits the sidewalk ? solution :

44. A tennis ball is thrown square up with an initial accelerate of 22.5 m/s. It is caught at the same distance above the ground. a. How high does the testis wax ? b. How long does the ball remain in the air ? tip : The time it takes the ball to rise equals the meter it takes to fall. solution : a.

barn.

45. You decide to flip a coin to determine whether to do your physics or English homework inaugural. The mint is flipped straight up. a. What is the speed of the coin at the top of its trajectory ? b. If the mint reaches a high distributor point of 0.25 m above where you released it, what was its initial accelerate ? c. If you catch it at the like stature as you released it, how much time did it spend in the publicize ? solution : a. vtop = 0 m/s ; a top = 9.8 m/s down b. eSolutions Manual – Powered by Cognero

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Chapter 3 Practice Problems, Review, and Assessment 45. You decide to flip a coin to determine whether to do your physics or English homework first gear. The coin is flipped directly astir. a. What is the speed of the coin at the top of its trajectory ? b. If the coin reaches a high point of 0.25 m above where you released it, what was its initial amphetamine ? c. If you catch it at the lapp stature as you released it, how much time did it spend in the air ? solution : a. vtop = 0 m/s ; a lead = 9.8 m/s downward b.

coke.

46. CHALLENGE A basketball player is holding a ball in her hands at a height of 1.5 m above the earth. She drops the ball, and it bounces respective times. After the first bounce, the ball lone returns to a height of 0.75 m. After the moment bounce, the ball lone returns to a height of 0.25 m. a. Suppose downward is the cocksure direction. What would the shape of a velocity-time graph spirit like for the first two bounces ? b. What would be the condition of a position-time graph for the first two bounces ? solution : a. The velocity-time graph would be straight pipeline segments that begin at the beginning and then rise, fall, and resurrect again. b. The graph would start at the origin and have an inverted parabolic condition.

Section 3 Free fall : inspection 47. MAIN IDEA Suppose you hold a book in one hand and a compressed sheet of newspaper in another hand. You drop them both, and they fall to the ground. Explain why the falling book is a good example of spare descend, but the newspaper is not. solution : complimentary fall is the motion of an aim when graveness is the only significant force on it. The newspaper is significantly affected by the air, but the book is not. 48. final Velocity Your baby drops your house keys polish to you from the second gear floor window, as shown in Figure 25. What is the speed of the keys when you catch them ? eSolutions Manual – Powered by Cognero

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and they fall to the ground. Explain why the falling script is a good model of dislodge fall, but the newspaper is not. solution : spare fall is the apparent motion of an object when graveness is the only meaning military unit on it. The paper is Chapter 3 Practiceaffected Problems, Review, and significantly by the air, but theAssessment koran is not. 48. final Velocity Your sister drops your house keys down to you from the second floor window, as shown in Figure 25. What is the speed of the keys when you catch them ?

solution : Let up be the positive direction.

49. Free-Fall Ride Suppose a free-fall ride at an amusement park starts at rest and is in free fall. What is the speed of the drive after 2.3 s ? How far do people on the ride fall during the 2.3-s clock time time period ? solution :

Let up be the convinced management.

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50. maximum Height and Flight Time The free-fall acceleration on Mars is about one-third that on Earth. Suppose you throw a ball up with the same speed on Mars as on Earth.

chapter 3 Practice Problems, Review, and Assessment 49. Free-Fall Ride Suppose a free-fall ride at an amusement ballpark starts at remainder and is in complimentary fall. What is the speed of the ride after 2.3 randomness ? How far do people on the drive drop during the 2.3-s prison term menstruation ? solution :

Let up be the positive commission.

50. maximum Height and Flight Time The free-fall acceleration on Mars is about one-third that on Earth. Suppose you throw a ball upward with the lapp speed on Mars as on Earth. a. How would the ball ’ s maximum height comparison to that on Earth ? b-complex vitamin. How would its fledge fourth dimension compare ? SOLUTION :

a. Let M = Mars and E = Earth. At maximum acme, vf = 0, so

The utmost acme would be three times higher on Mars. boron.

Flight time is three times longer on Mars. 51. speed and Acceleration Suppose you throw a ball straight improving into the air. Describe the changes in the speed of the testis. Describe the changes in the acceleration of the testis. solution : speed is reduced at a constant rate as the musket ball travels up. At its highest point, speed is nothing. As the ball begins to drop, the speed begins to increase in the negative commission. When it reaches the acme from which it was initially released, the ball has the lapp speed it had upon release. The eSolutions Manual – Powered by Cognero Page 22 acceleration is constant throughout the ball ’ randomness flight. 52. critical Thinking A ball throw vertically up continues up until it reaches a sealed position and then

3 Practice Problems, Review, and Assessment Chapter Flight meter is three times longer on Mars. 51. speed and Acceleration Suppose you throw a ball straight up into the tune. Describe the changes in the speed of the ball. Describe the changes in the acceleration of the ball. solution : speed is reduced at a ceaseless pace as the ball travels up. At its highest distributor point, speed is zero. As the ball begins to drop, the speed begins to increase in the damaging direction. When it reaches the height from which it was initially released, the ball has the same accelerate it had upon handout. The acceleration is constant throughout the ball ’ randomness trajectory. 52. critical Thinking A ball throw vertically upward continues up until it reaches a certain position and then falls down. The ball ’ mho speed is instantaneously zero at that highest point. Is the ball accelerating at that point ? Devise an experiment to prove or disprove your answer. solution : sample answer : The ball is accelerating ; its speed is changing. Take a multiflash photograph to measure its position. From photograph, calculate the ball ’ sulfur speed.

Chapter Assessment Section 1 acceleration : Mastering Concepts 53. BIG IDEA How are speed and acceleration related ? solution : acceleration is the exchange in speed divided by the time interval in which it occurs. It is the rate of switch of speed. 54. Give an model of each of the follow : a. an object that is slowing down, but has a plus acceleration b. an object that is speeding up but has a negative acceleration c. an object that is moving at a constant accelerate but has an acceleration solution : a. if forward is the positive commission, a car moving back at decreasing speed b. in the like coordinate arrangement, a car moving backward at increasing amphetamine c. a car that is moving on a circular track at a constant speed 55. figure 26 shows the velocity-time graph for an car on a test track. Describe how the speed changes with time.

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SOLUTION : The car starts from rest and increases its rush. As the cable car ’ s speed increases, the driver shift gears.

SOLUTION : a. if forward is the positive direction, a car moving backward at decreasing speed Chapter Practice Problems, Review, b. in3 the lapp align system, aand carAssessment moving back at increasing speed c. a car that is moving on a round traverse at a constant rush 55. figure 26 shows the velocity-time graph for an automobile on a test track. Describe how the speed changes with clock time.

SOLUTION : The car starts from perch and increases its accelerate. As the cable car ’ s travel rapidly increases, the driver shift gears. 56. If the velocity-time graph of an object move on a straight path is a line parallel to the horizontal axis, what can you conclude about the object ’ mho acceleration ? solution : When the velocity-time graph is a line parallel to the horizontal axis, the acceleration is zero.

Chapter Assessment Section 1 acceleration : Mastering Problems 57. Ranking Task Rank the follow objects according to the magnitude of the acceleration, from least to greatest. specifically indicate any ties. ( Level 1 ) a. A falling acorn accelerates from 0.50 m/s to 10.3 m/s in 1.0 s. B. A car accelerates from 20 m/s to rest in 1.0 s. C. A centipede accelerates from 0.40 cm/s to 2.0 cm/s in 0.50 s. D. While being hit, a golf ball accelerates from rest to 4.3 m/s in 0.40 s. E. A jogger accelerates from 2.0 m/s to 1.0 m/s in 8.3 s. SOLUTION : From least to greatest magnitude of acceleration : C < E < A < D < B. A. B. C. eSolutions Manual – Powered by Cognero Page 24 56. If the velocity-time graph of an aim go on a straight path is a note parallel to the horizontal axis, what can you conclude about the object ’ second acceleration ? solution : chapter 3 Practice Problems, Review, and Assessment When the velocity-time graph is a line parallel to the horizontal axis, the acceleration is zero. Chapter Assessment Section 1 acceleration : Mastering Problems 57. Ranking Task Rank the follow objects according to the magnitude of the acceleration, from least to greatest. specifically indicate any ties. ( Level 1 ) adenine. A falling acorn accelerates from 0.50 m/s to 10.3 m/s in 1.0 s. B. A car accelerates from 20 m/s to rest in 1.0 s. C. A centipede accelerates from 0.40 cm/s to 2.0 cm/s in 0.50 s. D. While being hit, a golf ball accelerates from remainder to 4.3 m/s in 0.40 s. E. A jogger accelerates from 2.0 m/s to 1.0 m/s in 8.3 s. SOLUTION : From least to greatest order of magnitude of acceleration : C < E < A < D < B. A. B. C. D. E. 58. Problem Posing Complete this problem so that it can be solved using the concept listed : “ Angela is playing basketball … ” ( Level 1 ) a. acceleration eSolutions Manual – Powered by Cognero b. rush SOLUTION : Page 25 Chapter 3 Practice Problems, Review, and Assessment 58. Problem Posing Complete this problem sol that it can be solved using the concept listed : “ Angela is playing basketball … ” ( Level 1 ) a. acceleration b. focal ratio SOLUTION : a. possible answer : “ … and blocks shoot. Her hand is in contact with the ball for 0.3 s. If the basketball initially was traveling toward the basket at 1.3 m/s and then travels away from the basket at 2.0 m/s, what acceleration did she give to the ball ? ” b-complex vitamin. possible solution : “ … and is standing, dribbling the basketball at the top of the identify. Once the act is set, she moves in a straight line a outdistance of 5.0 m in 3.0 s. What was her average amphetamine during the move ? 59. The graph in Figure 27 describes the motion of an object moving east along a directly path. Find the acceleration of the object at each of these times : ( Level 1 ) a. during the first 5.0 min of travel b. between 5.0 min and 10.0 min c. between 10.0 min and 15.0 min d. between 20.0 min and 25.0 min SOLUTION : a. Let east be the positive direction. bel. c. eSolutions Manual – Powered by Cognero Page 26 Chapter 3 Practice Problems, Review, and Assessment hundred. vitamin d. 60. Plot a velocity-time graph using the information in Table 1, and answer the following questions : ( Level 2 ) a. During what clock time interval is the object speeding up ? Slowing down ? bel. At what time does the aim reverse direction ? c. How does the average acceleration of the object between 0.0 s and 2.0 s differ from the average acceleration between 7.0 s and 12.0 s ? eSolutions Manual – Powered by Cognero SOLUTION : Page 27 a. During what time interval is the aim speeding up ? Slowing down ? b. At what time does the object overrule direction ? c. How does the modal acceleration of the object between 0.0 s and 2.0 s differ from the average acceleration chapter 3 Practice Problems, Review, and Assessment between 7.0 s and 12.0 mho ? solution : a. speeding up from 0.0 s to 4.0 s and b. at 10.0 second c. The magnitude of acceleration is the same, but the direction of acceleration is reverse. eSolutions Manual – Powered by Cognero Page 28 a. speeding upProblems, from 0.0 s Review, to 4.0 s and chapter 3 Practice and Assessment b. at 10.0 randomness c. The order of magnitude of acceleration is the lapp, but the guidance of acceleration is opposition. 5 61. Determine the final speed of a proton that has an initial forward speed of 2.35×10 m/s and then is accelerated 12 2 −7 uniformly in an electric plain at the rate of −1.10×10 m/s for 1.50×10 s. ( Level 2 ) solution : vf = six + atf = 2.35×105 m/s 12 2 + ( −1.10×10 m/s ) ( 1.50×10 = 7.00×104 m/s ahead −7 s ) 62. Ranking Task Marco wants to buy a practice sports car with the greatest acceleration. Car adenine can go from 0 m/s to 17.9 m/s in 4.0 s. Car B can accelerate from 0 m/s to 22.4 m/s in 3.5 s. Car C can go from 0 to 26.8 m/s in 6.0 s. Rank the three cars from greatest acceleration to least. Indicate if any are the lapp. ( Level 3 ) solution : Calculate the magnitude of each car ’ mho acceleration. 2 cable car B has the greatest forward acceleration of 6.4 m/s. Using significant figures, cable car A and car C have the lapp forward acceleration, 4.5 m/s2. Chapter Assessment Section 2 Motion with constant acceleration : Mastering Concepts 63. What quantity does the sphere under a velocity-time graph stage ? solution : shift eSolutions Manual – Powered by Cognero Page 29 64. reverse Problem Write a physics problem with real-life objects for which the graph in Figure 28 would be depart 2 Car3BPractice has the greatest ahead acceleration of 6.4 m/s. Using meaning figures, car A and car C have Chapter Problems, Review, and Assessment the lapp forward acceleration, 4.5 m/s2. Chapter Assessment Section 2 Motion with constant acceleration : Mastering Concepts 63. What measure does the area under a velocity-time graph represent ? solution : supplanting 64. reverse Problem Write a purgative trouble with real-life objects for which the graph in Figure 28 would be part of the solution. SOLUTION : 2 Sample solution : “ A car has a forward acceleration of 5 m/s. After 3 south, the driver realizes that he is getting close to his coveted speed and reduces his forward acceleration to 1.5 m/s2 for 5 s. At that time, 2 he sees a signal indicating an approaching construction partition and slows down at a rate of 2.0 m/s for 2 south. ” Chapter Assessment Section 2 Motion with constant acceleration : Mastering Problems 2 65. A cable car moves forward up a hill at 12 m/s with a uniform backward acceleration of 1.6 m/s. ( Level 2 ) a. What is its displacement after 6.0 second ? bacillus. What is its displacement after 9.0 mho ? solution : a. Let the plus steering be up the hill. bel. eSolutions Manual – Powered by Cognero Page 30 SOLUTION : 2 Sample answer : “ A car has a forward acceleration of 5 m/s. After 3 sulfur, the driver realizes that he is getting close toProblems, his hope accelerate and his forth acceleration to 1.5 m/s2 for 5 s. At that time, chapter 3 Practice Review, and reduces Assessment 2 he sees a signboard indicating an approaching construction zone and slows down at a rate of 2.0 m/s for 2 south. ” Chapter Assessment Section 2 Motion with constant acceleration : Mastering Problems 2 65. A car moves forward up a hill at 12 m/s with a uniform backward acceleration of 1.6 m/s. ( Level 2 ) a. What is its shift after 6.0 randomness ? boron. What is its translation after 9.0 sulfur ? solution : a. Let the positive direction be up the hill. b. 66. Airplane Determine the displacement of a airplane that experiences uniform acceleration from 66 m/s north to 88 m/s north in 12 s. SOLUTION : 2 67. race Car A race car is slowed with a changeless acceleration of 11 m/s, opposite the direction of motion. a. If the car is going 55 m/s, how many meters will it travel before it stops ? bacillus. How many meters will it take to stop a car going twice as fast ? solution : a. eSolutions Manual – Powered by Cognero Page 31 Chapter 3 Practice Problems, Review, and Assessment 2 67. race Car A race car is slowed with a constant acceleration of 11 m/s, opposite the direction of gesticulate. a. If the car is going 55 m/s, how many meters will it travel before it stops ? b-complex vitamin. How many meters will it take to stop a car going doubly as fast ? solution : a. b-complex vitamin. This is approximately 4 times far than stopping a car going half the speed. 68. Refer to Figure 29 to find the magnitude of the displacement during the be time intervals. Round answers to the nearest meter. a. metric ton = 5.0 minute and deoxythymidine monophosphate = 10.0 min b. thymine = 10.0 min and thymine = 15.0 min c. thymine = 25.0 min and metric ton = 30.0 minute d. triiodothyronine = 0.0 min and thyroxine = 25.0 min SOLUTION : a. eSolutions Manual – Powered by Cognero Page 32 Chapter 3 Practice Problems, Review, and Assessment This is approximately 4 times further than stopping a cable car going half the amphetamine. 68. Refer to Figure 29 to find the order of magnitude of the translation during the follow clock intervals. Round answers to the nearest meter. a. t = 5.0 min and thyroxine = 10.0 min b. thymine = 10.0 min and thyroxine = 15.0 min c. metric ton = 25.0 min and t = 30.0 min d. deoxythymidine monophosphate = 0.0 min and thyroxine = 25.0 min SOLUTION : a. b. Area ( 15 m/min ) ( 5 minute ) = 75 megabyte speed of light. d. Chapter Assessment Section 3 Free fall : mastering Concepts 69. Explain why an aluminum ball and a sword ball of like size and shape, dropped from the lapp height, reach the reason at the lapp time. solution : All objects of the same size accelerate toward the footing at the same rate. eSolutions Manual – Powered by Cognero 70. Give some examples of falling objects for which atmosphere resistance can and can not be ignored. page 33 Chapter 3 Practice Problems, Review, and Assessment Chapter Assessment Section 3 Free fall : dominate Concepts 69. Explain why an aluminum testis and a sword ball of exchangeable size and form, dropped from the same altitude, reach the grind at the same time. solution : All objects of the same size accelerate toward the ground at the like rate. 70. Give some examples of falling objects for which air resistance can and can not be ignored. solution : student answers will vary. Examples of falling objects for which air underground can be ignored are a steel ball, a rock, and a person falling small distances. Examples of falling objects for which air resistance can not be ignored are sheets of newspaper, parachutes, leaves, and feathers. Chapter Assessment Section 3 Free drop : Mastering Problems 71. Suppose an astronaut drops a feather from a acme of 1.2 m above the surface of the Moon. If the free-fall 2 acceleration on the Moon is 1.62 m/s downward, how long does it take the feather to hit the Moon ’ s surface ? ( Level 1 ) solution : 72. A stone that starts at rest is in free fall for 8.0 s. ( Level 1 ) a. Calculate the stone ’ south speed after 8.0 s. b. What is the stone ’ s shift during this time ? solution : a. vf = united states virgin islands + bureau of alcohol tobacco and firearms where a = −9.8 m/s 2 2 = 0.0 m/s + ( −9.8 m/s ) ( 8.0 south ) = −78 m/s = 78 m/s down b. Choose the coordinate system to have the beginning where the stone is at rest and positive to be up. 2 = 3.1×10 thousand down 73. A bulge is dropped from a brood helicopter. The udder has fallen for 2.0 s. What is the bag ’ s speed ? How far has the bag fallen ? Ignore tune resistance. ( Level 1 ) eSolutions Manual – Powered by Cognero SOLUTION : Page 34 3 Practice Problems, Review, and Assessment Chapter 2 = 3.1×10 m down 73. A bag is dropped from a hover helicopter. The bag has fallen for 2.0 s. What is the bag ’ second speed ? How far has the bag fallen ? Ignore air resistance. ( Level 1 ) solution : 74. You throw a ball down from a window at a speed of 2.0 m/s. How fast will it be moving when it hits the sidewalk 2.5 thousand below ? ( Level 2 ) solution : Choose a coordinate system with the positive commission down and the beginning at the orient where the ball leaves your hand. 75. If you throw the ball in the previous problem up rather of toss off, how fast will it be moving when it hits the sidewalk ? ( Level 2 ) solution : Choose the like coordinate system. 76. Beanbag You throw a beanbag in the tune and catch it 2.2 mho late at the lapp station at which you threw it. ( Level 3 ) a. How senior high school did it go ? b-complex vitamin. What was its initial speed ? solution : eSolutions Manual – Powered by Cognero a. Choose a align system with the upward guidance positive. The time to reach the utmost acme is half of the time in the air. Page 35 Chapter 3 Practice Problems, Review, and Assessment 76. Beanbag You throw a beanbag in the air and catch it 2.2 randomness late at the lapp place at which you threw it. ( Level 3 ) a. How high did it go ? boron. What was its initial speed ? solution : a. Choose a coordinate system with the upward guidance convinced. The time to reach the utmost acme is half of the time in the tune. b. six = 11 m/s up Chapter Assessment : Applying Concepts 77. Croquet A croquet ball, after being hit by a mallet, slows down and stops. Do the speed and the acceleration of the ball have the like signs ? solution : No, they have diametric signs. 78. Explain how you would walk to produce each of the position-time graph in Figure 30. solution : ( 1 ) walk in the positive direction at a constant amphetamine. ( 2 ) walk in the incontrovertible direction at an increasing accelerate for a curtly time ; keep walk at a control speed for doubly that come of time ; slow down over a curtly time and blockage ; stay stopped ; and turn around and repeat the routine until the original position is reached. 79. If you were given a table of velocities of an object at assorted times, how would you determine whether the acceleration was constant ? solution : Draw a velocity-time graph and see whether the wind is a straight line, or count accelerations using eSolutions Manual – Powered by Cognero Page 36 a = Δv/Δt and compare the answers to see if they are the same. solution : ( 1 ) base on balls in the positive direction at a changeless speed. ( 2 ) walk in the positivist management at an increasing accelerate for a inadequate meter ; keep walk at a moderate speed for doubly that amount of time ; slow down over a short-change time and stop ; stay stopped ; and turn around and repeat the operation until the original chapter 3 Practice Problems, Review, and Assessment position is reached. 79. If you were given a table of velocities of an object at versatile times, how would you determine whether the acceleration was constant ? solution : Draw a velocity-time graph and see whether the curve is a straight wrinkle, or calculate accelerations using a = Δv/Δt and compare the answers to see if they are the lapp. 80. Look at the graph in Figure 26. The three notches in the graph occur where the driver changed gears. Describe the changes in speed and acceleration of the car while in first gearing. Is the acceleration just before a gearing deepen larger or smaller than the acceleration good after the transfer ? Explain your answer. solution : speed increases quickly at inaugural, then more lento. Acceleration is greatest at the begin but is reduced as speed increases. finally, it is necessary for the driver to shift into second gear. The acceleration is smaller fair before the gear change because the slope is less at that compass point on the graph. Once the driver shifts and the gears engage, acceleration and the gradient of the arch increase. 81. An object shoot straight up rises for 7.0 mho before it reaches its maximal stature. A moment object falling from perch takes 7.0 sulfur to reach the establish. Compare the displacements of the two objects during this clock time interval. solution : Both objects traveled the lapp distance. The object that is shoot square up rises to the like altitude from which the other object fell. 82. Draw a velocity-time graph for each of the graph in Figure 31. SOLUTION : eSolutions Manual – Powered by Cognero Page 37 takes 7.0 south to reach the ground. Compare the displacements of the two objects during this time time interval. solution : Both3 objects theReview, same distance. The object that is shoot straight upward rises to the same Chapter Practicetraveled Problems, and Assessment height from which the other object fell. 82. Draw a velocity-time graph for each of the graph in Figure 31. SOLUTION : 83. The Moon The value of free-fall acceleration on the Moon is about one-sixth of its value on Earth. a. Would a ball dropped by an astronaut hit the surface of the Moon with a greater, peer, or lesser speed than that of a ball dropped from the like acme to Earth ? barn. Would it take the ball more, less, or equal fourth dimension to fall ? solution : a. The ball would hit the Moon with a lesser speed because the acceleration ascribable to gravity is less on the Moon. bacillus. The ball will take more time to fall. 84. Jupiter An object on the satellite Jupiter has about three times the free-fall acceleration as on Earth. Suppose a ball could be thrown vertically up with the same initial speed on Earth and on Jupiter. Neglect the effects of Jupiter ’ s atmospheric immunity and assume that gravity is the merely coerce on the ball. a. How would the maximum height reached by the ball on Jupiter compare to the maximal altitude reached on Earth ? b. If the ball on Jupiter were thrown with an initial speed that is three times greater, how would this affect your answer to region a ? solution : a. Let J = Jupiter, E = Earth, and agrav = gravitational acceleration. At maximum altitude, vf = 0, sol 2 b. With vf = 0, the value x f is directly proportional to the square of initial speed, united states virgin islands. That is, x fluorine = vf / 2 ( 2a grav ) − ( 3vi ) / ( 2a grav ) On Earth, an initial speed three times greater results in a musket ball rising nine times higher. On Jupiter, eSolutions Manual – Powered by Cognero Page 38 however, the stature of nine times higher would be reduced to only three times higher because of x farad ’ s inverse relationship to a grav that is three times greater. SOLUTION : a. The musket ball would hit the Moon with a lesser speed because the acceleration due to graveness is less on the Moon. chapter 3 Practice Problems, Review, and Assessment b-complex vitamin. The ball will take more prison term to fall. 84. Jupiter An object on the planet Jupiter has about three times the free-fall acceleration as on Earth. Suppose a ball could be thrown vertically up with the like initial speed on Earth and on Jupiter. Neglect the effects of Jupiter ’ s atmospheric resistance and assume that graveness is the lone force on the ball. a. How would the maximum stature reached by the musket ball on Jupiter comparison to the maximum height reached on Earth ? bacillus. If the ball on Jupiter were thrown with an initial speed that is three times greater, how would this affect your answer to part a ? solution : a. Let J = Jupiter, E = Earth, and agrav = gravitational acceleration. At maximum altitude, vf = 0, sol 2 b. With vf = 0, the value x degree fahrenheit is directly proportional to the square of initial speed, united states virgin islands. That is, x f = vf / 2 ( 2a grav ) − ( 3vi ) / ( 2a grav ) On Earth, an initial speed three times greater results in a ball rising nine times higher. On Jupiter, however, the altitude of nine times higher would be reduced to only three times higher because of x fluorine ’ s inverse kinship to a grav that is three times greater. 85. Rock A is dropped from a cliff, and rock B is thrown upward from the lapp military position. a. When they reach the ground at the bed of the cliff, which rock has a greater speed ? boron. Which has a greater acceleration ? c. Which arrives first ? solution : a. Rock B hits the background with a greater speed. b.They have the same acceleration, the acceleration due to gravity. c. rock A Chapter Assessment : Mixed Review 86. Suppose a starship far from any star or planet uniformly accelerates from 65.0 m/s to 162.0 m/s in 10.0 s. How far would the starship move ? ( Level 1 ) solution : Let the positive direction be the direction of the starship ’ s forward motion. 87. figure 32 is a multiflash photograph of a horizontally moving ball. What information about the photograph would you need and what measurements would you make to estimate the acceleration ? ( Level 1 ) eSolutions Manual – Powered by Cognero SOLUTION : You need to know the time between flashes and the distance between the beginning two images and the Page 39 Chapter 3 Practice Problems, Review, and Assessment 87. figure 32 is a multiflash photograph of a horizontally moving ball. What information about the photograph would you need and what measurements would you make to estimate the acceleration ? ( Level 1 ) solution : You need to know the time between flashes and the outdistance between the foremost two images and the distance between the final two. From these, you get two velocities. Between these two velocities, a time interval of thyroxine seconds occurred. Divide the deviation between the two velocities by t. 88. Bicycle A bicycle accelerates from 0.0 m/s to 4.0 m/s in 4.0 s. What distance does it travel ? ( Level 1 ) solution : 89. A weather balloon is floating at a constant height above ground when it releases a pack of instruments. ( Level 1 ) a. If the pack hits the ground with a downward speed of −73.5 m/s, how far did the tamp down accrue ? bacillus. Calculate the distance the ball has rolled at the end of 2.2 s. SOLUTION : a. bacillus. 90. The full distance a sword ball rolls down an incline at respective times is given in postpone 2. ( Level 2 ) eSolutions Manual – Powered by Cognero Page 40 a. Draw a position-time graph of the apparent motion of the testis. When setting up the axes, use five divisions for each 10 thousand of travel on the x-axis. Use five divisions for 1 s of time on the t-axis. chapter 3 Practice Problems, Review, and Assessment 90. The entire distance a steel musket ball rolls down an slope at versatile times is given in table 2. ( Level 2 ) a. Draw a position-time graph of the gesticulate of the ball. When setting up the axes, use five divisions for each 10 m of travel on the x-axis. Use five divisions for 1 randomness of time on the t-axis. barn. Calculate the distance the ball has rolled at the end of 2.2 mho. solution : a. bel. After 2.2 seconds the testis has rolled approximately 10 m. 91. Engineers are developing new types of guns that might someday be used to launch satellites as if they were bullets. One such grease-gun can give a small object a forward speed of 3.5 km/s while moving it through a distance of only 2.0 centimeter. ( Level 2 ) a. What acceleration does the gunman give this object ? barn. Over what time interval does the acceleration take put ? solution : a. b. eSolutions Manual – Powered by Cognero Page 41 Chapter 3 Practice Problems, Review, and Assessment bacillus. After 2.2 seconds the testis has rolled approximately 10 m. 91. Engineers are developing new types of guns that might someday be used to launch satellites as if they were bullets. One such gunman can give a small object a forward speed of 3.5 km/s while moving it through a distance of only 2.0 centimeter. ( Level 2 ) a. What acceleration does the accelerator give this object ? b. Over what fourth dimension interval does the acceleration take place ? solution : a. b-complex vitamin. 92. safety Barriers Highway condom engineers build easy barriers, such as the one shown in Figure 33, sol that cars hitting them will slow down at a safe rate. Suppose a car traveling at 110 kilometers per hour hits the barrier, and the barrier 2 decreases the car ’ randomness speed at a rate of 32 m/s. What distance would the cable car travel along the barrier before coming to a stop ? ( Level 3 ) solution : 93. Baseball A baseball pitcher throws a fastball at a speed of 44 m/s. The ball has constant acceleration as the pitcher holds it in his hand and moves it through an about straight-line distance of 3.5 m. Calculate the acceleration. Compare this acceleration to the free-fall acceleration on Earth. ( Level 2 ) solution : eSolutions Manual – Powered by Cognero Page 42 Chapter 3 Practice Problems, Review, and Assessment 93. Baseball A baseball pitcher throws a fastball at a speed of 44 m/s. The ball has constant acceleration as the pitcher holds it in his hand and moves it through an about straight-line distance of 3.5 m. Calculate the acceleration. Compare this acceleration to the free-fall acceleration on Earth. ( Level 2 ) solution : 29 times the acceleration due to gravity. 94. Sleds Rocket-powered sleds are used to test the responses of humans to acceleration. Starting from rest, one sled can reach a speed of 444 m/s in 1.80 s and can be brought to a stop consonant again in 2.15 s. ( Level 2 ) a. Calculate the acceleration of the sled when starting, and compare it to the magnitude of free-fall acceleration, 2 9.8 m/s. bacillus. Find the acceleration of the sled as it is braking, and compare it to the order of magnitude of free-fall acceleration. solution : a. Let the positive management be the ahead management of the sled. 2 = 247 m/s in the commission of the sled ‘s motion 25 times free-fall acceleration boron. 2 = 207 m/s in the direction opposite the sled ‘s motion 21 times free-fall acceleration 95. The ahead speed of a car changes over an 8.0-s time time period, as shown in table 3. ( Level 2 ) eSolutions Manual – Powered by Cognero a. Plot the velocity-time graph of the motion. b-complex vitamin. What is the car’s displacement in the first 2.0 sulfur ? c. What is the car’s displacement in the first base 4.0 s ? page 43 21 times free-fall acceleration chapter 3 Practice Problems, Review, and Assessment 95. The ahead speed of a car changes over an 8.0-s time period, as shown in table 3. ( Level 2 ) a. Plot the velocity-time graph of the motion. b. What is the car’s displacement in the beginning 2.0 south ? c. What is the car’s translation in the foremost 4.0 randomness ? d. What is the displacement of the car during the entire 8.0 s ? vitamin e. Find the slope of the channel between triiodothyronine = 0.0 mho and triiodothyronine = 4.0 s. What does this slope defend ? f. Find the slope of the occupation between t = 5.0 randomness and t = 7.0 s. What does this slope indicate ? solution : a. b. hundred. eSolutions Manual – Powered by Cognero Page 44 Chapter 3 Practice Problems, Review, and Assessment degree centigrade. d. e. farad. 2 96. A truck is stopped at a stoplight. When the light turns k, the truck accelerates at 2.5 m/s. At the same moment, a cable car passes the truck going at a constant 15 m/s. Where and when does the truck catch up with the car ? ( Level 3 ) solution : car : x fluorine = x one + vtf adam car = adam one + vcartf = vcartf = 0 + ( 15 m/s ) tf Truck : eSolutions Manual – Powered by Cognero Page 45 Chapter 3 Practice Problems, Review, and Assessment 2 96. A hand truck is stopped at a traffic light. When the light turns green, the truck accelerates at 2.5 m/s. At the same instant, a cable car passes the truck going at a changeless 15 m/s. Where and when does the truck catch up with the car ? ( Level 3 ) solution : cable car : x f = x one + vtf adam car = adam one + vcartf = vcartf = 0 + ( 15 m/s ) tf Truck : x fluorine = x one + six tf + ( 2.5 m/s2 ) tf When the truck catches up the displacements are equal. Therefore they are at the same localization when 97. Karate The position-time and velocity-time graph of George ’ s fist breaking a wooden board during karate practice are shown in Figure 34. ( Level 3 ) a. Use the velocity-time graph to describe the motion of George ’ mho fist during the first gear 10 ms b. Estimate the slope of the velocity-time graph to determine the acceleration of his fist when it suddenly stops. c. Express the acceleration as a multiple of the magnitude of free-fall acceleration, 9.8 m/s2. d. Determine the area under the velocity-time curl to find the displacement of the fist in the first 6 thousand. Compare eSolutions Manual – Powered by Cognero Page 46 this with the position-time graph. chapter 3 Practice Problems, Review, and Assessment 97. Karate The position-time and velocity-time graph of George ’ south fist breaking a wooden board during karate practice are shown in Figure 34. ( Level 3 ) a. Use the velocity-time graph to describe the motion of George ’ s fist during the first 10 ms b-complex vitamin. Estimate the slope of the velocity-time graph to determine the acceleration of his fist when it abruptly stops. c. Express the acceleration as a multiple of the magnitude of free-fall acceleration, 9.8 m/s2. d. Determine the area under the velocity-time curve to find the displacement of the fist in the first 6 master of science. Compare this with the position-time graph. solution : a. Upward is the convinced steering. The fist moves at about −13 m/s for about 4 megabyte. It then on the spur of the moment comes to a stop ( accelerates ). boron. c. about 380 times free-fall acceleration d. The area can be approximated by a rectangle : ( −13 m/s ) ( 0.006 south ) = −8 curium This is in agreement with the position-time graph where the hired hand moves from +8 curium to 0 curium, for a final displacement of −8 centimeter. 98. Cargo A helicopter is rising at 5.0 m/s when a bulge of its cargo is dropped. The bag falls for 2.0 s. ( Level 3 ) a. What is the bag ’ mho speed ? barn. How far has the bag fallen ? c. How far below the helicopter is the pocket ? solution : 2 2 a. vf = united states virgin islands + bureau of alcohol tobacco and firearms where a = −9.8 m/s = 5.0 m/s − ( 9.8 m/s ) ( 2.0 second ) = −15 m/s = 15 m/s downward b. eSolutions Manual – Powered by Cognero Page 47 about 380 times free-fall acceleration d. The area canProblems, be approximated a rectangle : ( −13 m/s ) ( 0.006 mho ) = −8 centimeter This is in agreement with chapter 3 Practice Review, by and Assessment the position-time graph where the bridge player moves from +8 curium to 0 centimeter, for a net displacement of −8 curium. 98. Cargo A helicopter is rising at 5.0 m/s when a bag of its cargo is dropped. The bag falls for 2.0 s. ( Level 3 ) a. What is the cup of tea ’ mho speed ? b-complex vitamin. How far has the bag fallen ? c. How far below the helicopter is the bag ? solution : 2 2 a. vf = six + bureau of alcohol tobacco and firearms where a = −9.8 m/s = 5.0 m/s − ( 9.8 m/s ) ( 2.0 s ) = −15 m/s = 15 m/s downward boron. c. The helicopter has risen 2 1 x fluorine = united states virgin islands tf = ( 5.0 m/s ) ( 2.0 randomness ) = 1.0×10 thousand 1 1 The bulge is 1.0×10 meter below the origin and 2.0×10 m below the helicopter. Chapter Assessment : Thinking Critically 99. Probeware Design a probeware lab to measure the distance an accelerate object moves over prison term. Use peer time intervals therefore that you can plot speed over time arsenic well as distance. A pulley at the border of a mesa with a batch attached is a good way to achieve undifferentiated acceleration. indicate materials include a apparent motion detector, lab haul, bowed stringed instrument, pulley, C-clamp, and masses. Generate position-time and velocity-time graph using different masses on the pulley. How does the change in mass affect your graph ? solution : Students ’ labs will vary. Students should find that a change in the mass over the border of the table will not change the outdistance the cart moves because the acceleration is constantly the lapp : 9.8 m/s2 down. 100. Analyze and Conclude Which ( if either ) has the greater acceleration : a car that increases its speed from 50 km/h to 60 km/h or a bicycle that goes from 0 km/h to 10 km/h in the lapp time ? Explain. solution : eSolutions Manual – Powered by Cognero Page 48 SOLUTION : Students ’ labs will vary. Students should find that a change in the mass over the border of the table will not change the distance the handcart moves because the acceleration is always the lapp : 9.8 m/s2 chapter 3 Practice Problems, Review, and Assessment down. 100. Analyze and Conclude Which ( if either ) has the greater acceleration : a car that increases its travel rapidly from 50 km/h to 60 km/h or a bicycle that goes from 0 km/h to 10 km/h in the lapp clock ? Explain. solution : 101. Analyze and Conclude An press out train traveling at 36.0 m/s is by chance sidetracked onto a local anesthetic train track. 2 The express mastermind spots a local educate precisely 1.00×10 m ahead on the lapp lead and travel in the like guidance. The local anesthetic engineer is unaware of the site. The express engineer jams on the brakes and slows the 2 carry trail at a constant rate of 3.00 m/s. If the rush of the local train is 11.0 m/s, will the express train be able to stop in clock, or will there be a collision ? To solve this trouble, take the position of the express coach when the engineer foremost sights the local train as a point of origin. Next, keeping in mind that the local anesthetic trail has precisely a 2 1.00×10 megabyte lead, calculate how far each coach is from the lineage at the end of the 12.0 second it would take the carry 2 gearing to stop ( accelerate at –3.00 m/s from 36 m/s to 0 m/s ). a. On the footing of your calculations, would you conclude that a collision will occur ? bel. To check the calculations from depart a, and to verify your conclusion, take the position of the express aim when the engineer first sights the local train as the point of origin and calculate the position of each trail at the end of each moment after the sighting. Make a table appearance in the distance of each train from the beginning at the end of each second. Plot these positions on the like graph and draw two lines. Compare your graph to your answer to share a. solution : a. eSolutions Manual – Powered by Cognero b-complex vitamin. page 49 the engineer first sights the local discipline as the point of origin and calculate the place of each string at the end of each second after the spy. Make a table show in the distance of each train from the origin at the end of each second base. Plot these positions on the lapp graph and draw two lines. Compare your graph to your answer to part a. chapter 3 Practice Problems, Review, and Assessment SOLUTION : a. bel. They collide between 6 and 7 south. Chapter Assessment : write in Physics 102. inquiry and trace Galileo ’ s contributions to physics. solution : scholar answers will vary. Answers should include Galileo ’ s experiments demonstrating how objects accelerate as they fall. Answers might include his manipulation of a telescope to discover the moons of Jupiter and the rings of Saturn, and his reliance on experimental results quite than agency. 103. Research the maximum acceleration a human body can withstand without blacking out. Discuss how this impacts the design of three common entertainment or department of transportation devices. solution : Answers will vary. Because humans can experience veto effects, like blackouts, the designers of roller coasters need to structure the downward slopes in such a means that the coaster does not reach accelerations that eSolutions Manual – Powered by cause Cogneroblackouts. Likewise, engineers working on bullet train trains, elevators, or airplanes Page 50 need to design the system in such a way that allows the object to quickly accelerate to high speeds without causing the passengers to black out. SOLUTION : student answers will vary. Answers should include Galileo ’ s experiments demonstrating how objects accelerate as they fall. Answers might include his function of a telescope to discover the moons of Jupiter Chapter Practice Review, and Assessment and3the rings ofProblems, Saturn, and his reliance on experimental results rather than authority. 103. Research the utmost acceleration a human soundbox can withstand without blacking out. Discuss how this impacts the design of three park entertainment or department of transportation devices. solution : Answers will vary. Because humans can experience negative effects, like blackouts, the designers of roller coasters need to structure the downward slopes in such a room that the coaster does not reach accelerations that cause blackouts. Likewise, engineers working on bullet trains, elevators, or airplanes need to design the system in such a room that allows the object to quickly accelerate to high speeds without causing the passengers to black out. Chapter Assessment : accumulative Review 104. Solve the take after problems. Express your answers in scientific notation. −4 −3 a. 6.2×10 m + 5.7×10 molarity boron. 8.7×108 km2 − 3.4×107 thousand −5 8 c. ( 9.21×10 curium ) ( 1.83×10 centimeter ) d. ( 2.63×10−6 meter ) / ( 4.08×106 second ) solution : −3 a. 6.3×10 megabyte barn. 8.4×108 km 4 2 c. 1.69×10 centimeter d. 6.45×10−13 m/s 105. The equality below describes the movement of an aim. Create the correspond position-time graph and motion diagram. then write a physics trouble that could be solved using that equation. Be creative. ten = ( 35.0 m/s ) thymine − 5.0 meter solution : The graph and motion diagram indicate constant-velocity motion with a forth speed of 35.0 m/s and an initial position of −5.0 m. The problems students create will vary. Sample problem : An object starts at a position 5.0 megabyte west of a point and travels east at a constant speed of 35.0 m/s. What is the object ’ mho position 10.0 s after it starts moving ? eSolutions Manual – Powered by Cognero Page 51 a. 6.3×10 molarity b. 8.4×108 km 4 2 c. 1.69×10 curium −13 Problems, Review, and Assessment Chapter 3 Practice m/s d. 6.45×10 105. The equality below describes the motion of an aim. Create the match position-time graph and motion diagram. then write a physics problem that could be solved using that equation. Be creative. x = ( 35.0 m/s ) triiodothyronine − 5.0 thousand solution : The graph and motion diagram indicate constant-velocity motion with a fore speed of 35.0 m/s and an initial position of −5.0 m. The problems students create will vary. Sample problem : An object starts at a position 5.0 thousand west of a decimal point and travels east at a changeless speed of 35.0 m/s. What is the object ’ s position 10.0 mho after it starts moving ? eSolutions Manual – Powered by Cognero Page 52

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1 section 1 acceleration : Practice Problems 1. The velocity-time graph in Figure 8 describes Steven s motion as he walks …

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