Physics Chapter 2

B

10) You are driving home on a weekend from school at 55 mi/h for 110 miles. It then starts to snow and you slow to 35 mi/h. You arrive home after driving 4 hours and 15 minutes. How far is your hometown from school? A) 180 mi B) 190 mi C) 200 mi D) 210 mi

C

103) The graph in the figure shows the position of a particle as it travels along the x-axis. What is the magnitude of the average velocity of the particle between t = 1.0 s and t = 4.0 s? A) 0.25 m/s B) 0.50 m/s C) 0.67 m/s D) 1.0 m/s E) 1.3 m/s

B

104) The graph in the figure shows the position of a particle as it travels along the x-axis. What is the magnitude of the average speed of the particle between t = 1.0 s and t = 4.0 s? A) 1.0 m/s B) 1.3 m/s C) 0.67 m/s D) 0.50 m/s E) 0.25 m/s

B

105) The graph in the figure shows the velocity of a particle as it travels along the x-axis. What is the magnitude of the average acceleration of the particle between t = 1.0 s and t = 4.0 s? A) 0.33 m/s2 B) 1.7 m/s2 C) 2.0 m/s2 D) 2.5 m/s2 E) 3.0 m/s2

B

11) A motorist travels 160 km at 80 km/h and 160 km at 100 km/h. What is the average speed of the motorist for this trip? A) 84 km/h B) 89 km/h C) 90 km/h D) 91 km/h

B

12) A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is her average speed for the trip? A) 85 km/h B) 88 km/h C) 90 km/h D) 92 km/h

B

13) An airplane travels at 300 mi/h south for 2.00 h and then at 250 mi/h north for 750 miles. What is the average speed for the trip? A) 260 mi/h B) 270 mi/h C) 275 mi/h D) 280 mi/h

D

14) An object moving in the +x direction experiences an acceleration of +2.0 m/s2. This means the object A) travels 2.0 m in every second. B) is traveling at 2.0 m/s. C) is decreasing its velocity by 2.0 m/s every second. D) is increasing its velocity by 2.0 m/s every second.

B

15) Suppose that a car traveling to the east (+x direction) begins to slow down as it approaches a traffic light. Which statement concerning its acceleration must be correct? A) Its acceleration is in the +x direction. B) Its acceleration is in the -x direction. C) Its acceleration is zero. D) Its acceleration is decreasing in magnitude as the car slows down.

A

16) Suppose that a car traveling to the west (-x direction) begins to slow down as it approaches a traffic light. Which statement concerning its acceleration must be correct? A) Its acceleration is positive. B) Its acceleration is negative. C) Its acceleration is zero. D) Its acceleration is decreasing in magnitude as the car slows down.

D

17) A runner runs around a track consisting of two parallel lines 96 m long connected at the ends by two semicircles with a radius of 49 m. She completes one lap in 100 seconds. What is her average velocity? A) 2.5 m/s B) 5.0 m/s C) 10 m/s D) 0 m/s E) 1.3 m/s

D

17) Suppose that an object is moving with a constant velocity. Which statement concerning its acceleration must be correct? A) The acceleration is constantly increasing. B) The acceleration is constantly decreasing. C) The acceleration is a constant non-zero value. D) The acceleration is equal to zero.

B

18) A runner runs around a track consisting of two parallel lines 96 m long connected at the ends by two semicircles with a radius of 49 m. She completes one lap in 100 seconds. What is her average speed? A) 2.5 m/s B) 5.0 m/s C) 10 m/s D) 0 m/s E) 1.3 m/s

A

19) You leave on a trip in order to attend a meeting that will start after you begin your trip. Along the way you plan to stop for dinner. If the fastest you can safely drive is 65 mi/h, what is the longest time you can spend over dinner and still arrive just in time for the meeting? A) 2.4 h B) 2.6 h C) 1.9 h D) You can't stop at all.

B

2) An object moves 15.0 m north and then 11.0 m south. Find both the distance it has traveled and the magnitude of its displacement. A) 4.0 m, 26.0 m B) 26.0 m, 4.0 m C) 26.0 m, 26.0 m D) 4.0 m, 4.0 m

E

20) A motorist makes a trip of 180 miles. For the first 90 miles she drives at a constant speed of 30 mph. At what constant speed must she drive the remaining distance if her average speed for the total trip is to be 40 mph? A) 45 mph B) 50 mph C) 52.5 mph D) 55 mph E) 60 mph

B

21) When a ball is thrown straight up with no air resistance, the acceleration at its highest point A) is upward B) is downward C) is zero D) reverses from upward to downward E) reverses from downward to upward

D

22) A rock from a volcanic eruption is launched straight up into the air with no appreciable air resistance. Which one of the following statements about this rock while it is in the air is correct? A) On the way up, its acceleration is downward and its velocity is upward, and at the highest point both its velocity and acceleration are zero. B) On the way down, both its velocity and acceleration are downward, and at the highest point both its velocity and acceleration are zero. C) Throughout the motion, the acceleration is downward, and the velocity is always in the same direction as the acceleration. D) The acceleration is downward at all points in the motion. E) The acceleration is downward at all points in the motion except that is zero at the highest point.

C

23) Suppose a ball is thrown straight up and experiences no appreciable air resistance. What is its acceleration just before it reaches its highest point? A) zero B) slightly less than g C) exactly g D) slightly greater than g

C

40) A car starting from rest accelerates at a constant 2.0 m/s2 for 10 s. It then travels with constant speed it has achieved for another 10 s. Then it finally slows to a stop with constant acceleration of magnitude 2.0 m/s2. How far does it travel after starting? A) 200 m B) 300 m C) 400 m D) 500 m

C

41) A car increases its forward velocity uniformly from 40 m/s to 80 m/s while traveling a distance of 200 m. What is its acceleration during this time? A) 8.0 m/s2 B) 9.6 m/s2 C) 12 m/s2 D) 24 m/s2

C

42) An object starts from rest and undergoes uniform acceleration. During the first second it travels 5.0 m. How far will it travel during the third second? A) 5.0 m B) 15 m C) 25 m D) 45 m

B

43) An object is moving in a straight line with constant acceleration. Initially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it move during this time? A) 30 m B) 39 m C) 48 m D) 57 m

C

5) A light-year is the distance that light travels in one year. The speed of light is 3.00 × 108 m/s. How many miles are there in one light-year? (1 mi = 1609 m, 1 y = 365 d) A) 9.46 × 1012 mi B) 9.46 × 1015 mi C) 5.88 × 1012 mi D) 5.88 × 1015 mi

A

50) An airplane needs to reach a velocity of 203.0 km/h to take off. On a 2000 m runway, what is the minimum acceleration necessary for the plane to take flight? A) 0.79 m/s2 B) 0.87 m/s2 C) 0.95 m/s2 D) 1.0 m/s2

A

51) Assuming equal rates of uniform acceleration in both cases, how much further would you travel if braking from to rest than from ? A) 4 times farther B) 3.2 times farther C) 4.8 times farther D) 5.2 times farther

A

52) Acceleration is sometimes expressed in multiples of g, where is the acceleration of an object due to the earth's gravity. In a car crash, the car's forward velocity may go from to in How many g's are experienced, on average, by the driver? A) 20 g B) 14 g C) 24 g D) 26 g

A

53) A baseball is hit with a bat and, as a result, its direction is completely reversed and its speed is doubled. If the actual contact with the bat lasts 0.45 s, what is the ratio of the magnitude of the average acceleration of the ball to its original speed? A) 6.7 s-1 B) 4.4 s-1 C) 2.2 s-1 D) 0.15 s-1

A

68) A laser is thrown upward with a speed of 12 m/s on the surface of planet X where the acceleration due to gravity is 1.5 m/s2 and there is no atmosphere. How long does it take for the laser to reach the maximum height? A) 8.0 s B) 18 s C) 48 s D) 144 s

D

69) An instrument is thrown upward with a speed of 15 m/s on the surface of planet X where the acceleration due to gravity is 2.5 m/s2 and there is no atmosphere. How long does it take for the instrument to return to where it was thrown? A) 6.0 s B) 8.0 s C) 10 s D) 12 s

C

7) You drive 6.0 km at 50 km/h and then another 6.0 km at 90 km/h. Your average speed over the 12 km drive will be A) greater than 70 km/h. B) equal to 70 km/h. C) less than 70 km/h. D) exactly 38 km/h. E) It cannot be determined from the information given because we must also know directions traveled.

B

70) A hammer is thrown upward with a speed of 14 m/s on the surface of planet X where the acceleration due to gravity is 3.5 m/s2 and there is no atmosphere. What is the speed of the hammer after 8.0 s? A) 7.0 m/s B) 14 m/s C) 21 m/s D) 64 m/s

B

71) Human reaction time is usually greater than 0.10 s. If your friend holds a ruler between your fingers and releases it without warning, how far can you expect the ruler to fall before you catch it, assuming negligible air resistance? A) At least 3.0 cm B) At least 4.9 cm C) At least 6.8 cm D) At least 9.8 cm

B

72) A ball is thrown upward at a velocity of 19.6 m/s. What is its velocity after 3.0 s, assuming negligible air resistance? A) 9.8 m/s upward B) 9.8 m/s downward C) 0 m/s D) 19.6 m/s downward

C

73) A bullet shot straight up returns to its starting point in 10 s. What is the initial speed of the bullet, assuming negligible air resistance? A) 9.8 m/s B) 25 m/s C) 49 m/s D) 98 m/s

B

74) A ball is thrown straight up with a speed of 36 m/s. How long does it take to return to its starting point, assuming negligible air resistance? A) 3.7 s B) 7.3 s C) 11 s D) 15 s

D

75) A ball is thrown downward from the top of a building with an initial speed of 25 m/s. It strikes the ground after 2.0 s. How high is the building, assuming negligible air resistance? A) 20 m B) 30 m C) 50 m D) 70 m

C

4) A runner ran the marathon (approximately 42.0 km) in 2 hours and 57 min. What was the average speed of the runner in m/s? A) 14,200 m/s B) 124 m/s C) 3.95 m/s D) 14.2 m/s

C

25) An airplane increases its speed at the average rate of 15 m/s2. How much time does it take to increase its speed from 100 m/s to 160 m/s? A) 17 s B) 0.058 s C) 4.0 s D) 0.25 s

C

26) A 10-kg rock and a 20-kg rock are thrown upward with the same initial speed v0 and experience no significant air resistance. If the 10-kg rock reaches a maximum height h, what maximum height will the 20-kg ball reach? A) h/4 B) h/2 C) h D) 2h E) 4h

C

27) A 10-kg rock and 20-kg rock are dropped from the same height and experience no significant air resistance. If it takes the 20-kg rock a time T to reach the ground, what time will it take the 10-kg rock to reach the ground? A) 4T B) 2T C) T D) T/2 E) T/4

A

27) A car is traveling north at After 12 s its velocity is in the same direction. Find the magnitude and direction of the car's average acceleration. A) 0.30 m/s2, south B) 2.7 m/s2, south C) 0.30 m/s2, north D) 2.7 m/s2, north

C

28) A 10-kg rock and a 20-kg rock are dropped at the same time and experience no significant air resistance. If the 10-kg rock falls with acceleration a, what is the acceleration of the 20-kg rock? A) 4a B) 2a C) a D) a/2 E) a/4

C

28) A racquetball strikes a wall with a speed of 30 m/s and rebounds in the opposite direction with a speed of 26 m/s. The collision takes 20 ms. What is the average acceleration of the ball during the collision with the wall? A) 0 m/s2 B) 200 m/s2 C) 2800 m/s2 D) 1500 m/s2 E) 1300 m/s2

B

29) The velocity v(t) of a particle as a function of time is given by v(t) = (2.3 m/s) + (4.1 m/s2)t - (6.2 m/s3)t2. What is the average acceleration of the particle between t = 1.0 s and t = 2.0 s? A) -13 m/s2 B) -15 m/s2 C) 13 m/s2 D) 15 m/s2 E) 0 m/s2

A

29) Two objects are dropped from a bridge, an interval of 1.0 s apart. Air resistance is negligible. During the time that both objects continue to fall, their separation A) increases. B) decreases. C) stays constant. D) increases at first, but then stays constant. E) decreases at first, but then stays constant.

C

3) What must be your average speed in order to travel 350 km in 5.15 h? A) 66.0 km/h B) 67.0 km/h C) 68.0 km/h D) 69.0 km/h

C

30) From the edge of a roof top you toss a green ball upwards with initial speed v0 and a blue ball downwards with the same initial speed. Air resistance is negligible. When they reach the ground below A) the green ball will be moving faster than the blue ball. B) the blue ball will be moving faster than the green ball. C) the two balls will have the same speed.

B

31) Ball A is dropped from the top of a building. One second later, ball B is dropped from the same building. Neglect air resistance. As time progresses, the difference in their speeds A) increases. B) remains constant. C) decreases. D) cannot be determined from the information given.

C

32) Two objects are thrown from the top of a tall building. One is thrown up, and the other is thrown down, both with the same initial speed. What are their speeds when they hit the street? Neglect air resistance. A) The one thrown up is traveling faster. B) The one thrown down is traveling faster. C) They are traveling at the same speed. D) It is impossible to tell because the height of the building is not given.

C

33) Brick A is dropped from the top of a building. Brick B is thrown straight down from the same building, and neither one experiences appreciable air resistance. Which statement about their accelerations is correct? A) The acceleration of A is greater than the acceleration of B. B) The acceleration of B is greater than the acceleration of A. C) The two bricks have exactly the same acceleration. D) Neither brick has any acceleration once it is released.

B

34) A certain test car can go from rest to 32.0 m/s in 3.88 s. The same car can come to a full stop from that speed in 4.14 s. What is the ratio of the magnitude of the starting acceleration to the stopping acceleration? A) 0.937 B) 1.07 C) 0.878 D) 1.14

D

35) A car initially traveling at 60 km/h accelerates at a constant rate of 2.0 m/s2. How much time is required for the car to reach a speed of 90 km/h? A) 15 s B) 30 s C) 45 s D) 4.2 s

C

36) A cart starts from rest and accelerates uniformly at 4.0 m/s2 for 5.0 s. It next maintains the velocity it has reached for 10 s. Then it slows down at a steady rate of 2.0 m/s2 for 4.0 s. What is the final speed of the car? A) 20 m/s B) 16 m/s C) 12 m/s D) 10 m/s

C

37) A car travels at 15 m/s for 10 s. It then speeds up with a constant acceleration of 2.0 m/s2 for 15 s. At the end of this time, what is its velocity? A) 15 m/s B) 30 m/s C) 45 m/s D) 375 m/s

C

38) A cart with an initial velocity of 5.0 m/s to the right experiences a constant acceleration of 2.0 m/s2 to the right. What is the cart's displacement during the first 6.0 s of this motion? A) 10 m B) 55 m C) 66 m D) 80 m

C

39) A jet plane is launched from a catapult on an aircraft carrier. In 2.0 s it reaches a speed of 42 m/s at the end of the catapult. Assuming the acceleration is constant, how far did it travel during those 2.0 s? A) 16 m B) 24 m C) 42 m D) 84 m

C

44) A car starts from rest and accelerates uniformly at 3.0 m/s2 toward the north. A second car starts from rest 6.0 s later at the same point and accelerates uniformly at 5.0 m/s2 toward the north. How long after the second car starts does it overtake the first car? A) 12 s B) 19 s C) 21 s D) 24 s

A

47) Starting from rest, a dragster travels a straight 1/4 mi racetrack in 6.70 s with constant acceleration. What is its velocity when it crosses the finish line? A) 269 mi/h B) 188 mi/h C) 296 mi/h D) 135 mi/h

A

48) A bicyclist starts a timed race at 6.0mi/h. in order to win, he must average 21 mi/h. Assuming constant acceleration from the start, how fast must he be traveling at the end of the race? A) 36 mi/h B) 30 mi/h C) 24 mi/h D) 42 mi/h

A

49) A a car accelerates from 5.0m/s to 21 m/s at a rate of 3.0 m/s^2. How far does it travel while accelerating? A) 69 m B) 207 m C) 41 m D) 117 m

C

67) A laser is thrown upward with a speed of 12 m/s on the surface of planet X where the acceleration due to gravity is 1.5 m/s2 and there is no atmosphere. What is the maximum height reached by the laser? A) 8.0 m B) 18 m C) 48 m D) 144 m

A

54) A train starts from rest and accelerates uniformly, until it has traveled 5.6 km and acquired a velocity of 42 m/s. The train then moves at a constant velocity of 42 m/s for 420 s. The train then slows down uniformly at 0.065 m/s2, until it is brought to a halt. The acceleration during the first 5.6 km of travel is closest to A) 0.16 m/s^2 B) 0.14 m/s^2 C) 0.17 m/s^2 D) 0.19 m/s^2 E) 0.20 m/s^2

A

55) A train starts from rest and accelerates uniformly, until it has traveled 2.1 km and acquired a velocity of 24 m/s. The train then moves at a constant velocity of 24 m/s for 400 s. The train then slows down uniformly at 0.065 m/s2, until it is brought to a halt. The distance traveled by the train while slowing down, in km, is closest to:closest to: A) 4.4 km. B) 4.2 km. C) 4.0 km. D) 3.8 km. E) 3.6 km.

C

57) A car starts from rest and accelerates at a steady 6.00 m/s2. How far does it travel in the first 3.00 s? A) 9.00 m B) 18.0 m C) 27.0 m D) 36.0 m E) 54.0 m

C

58) A car is moving with a constant acceleration. At time t = 5.0 s its velocity is 8.0 m/s in the forward direction, and at time t = 8.0 s its velocity is 12.0 m/s forward. What is the distance traveled in that interval of time? A) 10 m B) 20 m C) 30 m D) 40 m E) 50 m

B

59) An airplane starts from rest and accelerates at a constant 10.8 m/s2. What is its speed at the end of a 400 m-long runway? A) 37.0 m/s B) 93.0 m/s C) 65.7 m/s D) 4320 m/s E) 186 m/s

D

6) If you are driving 72 km/h along a straight road and you look to the side for 4.0 s, how far do you travel during this inattentive period? A) 18 m B) 20 m C) 40 m D) 80 m

D

60) A car is moving with a speed of 32.0 m/s. The driver sees an accident ahead and slams on the brakes, causing the car to slow down with a uniform acceleration of magnitude 3.50 m/s2. How far does the car travel after the driver put on the brakes until it comes to a stop? A) 4.57 m B) 9.14 m C) 112 m D) 146 m E) 292 m

B

61) A car is traveling with a constant speed when the driver suddenly applies the brakes, causing the car to slow down with a constant acceleration of magnitude 3.50 m/s2. If the car comes to a stop in a distance of 30.0 m, what was the car's original speed? A) 10.2 m/s B) 14.5 m/s C) 105 m/s D) 210 m/s E) 315 m/s

A

62) A car is traveling with a constant speed of 30.0 m/s when the driver suddenly applies the brakes, causing the car to slow down with a constant acceleration. The car comes to a stop in a distance of 120 m. What was the acceleration of the car as it slowed down? A) 3.75 m/s2 B) 4.00 m/s2 C) 4.25 m/s2 D) 4.50 m/s2 E) 4.75 m/s2

B

63) A car is traveling at 26.0 m/s when the driver suddenly applies the brakes, causing the car to slow down with constant acceleration. The car comes to a stop in a distance of 120 m. How fast was the car moving when it was 60.0 m past the point where the brakes were applied? A) 22.5 m/s B) 18.4 m/s C) 15.0 m/s D) 12.1 m/s E) 9.20 m/s

C

64) Car A is traveling at 22.0 m/s and car B at 29.0 m/s. Car A is 300 m behind car B when the driver of car A accelerates his car with a uniform forward acceleration of 2.40 m/ . How long after car A begins to accelerate does it take car A to overtake car B? A) 5.50 s B) 12.6 s C) 19.0 s D) 316 s E) Car A never overtakes car B.

A

65) A stone is thrown with an initial upward velocity of 7.0 m/s and experiences negligible air resistance. If we take upward as the positive direction, what is the velocity of the stone after 0.50 s? A) 2.1 m/s B) 4.9 m/s C) -2.1 m/s D) -4.9 m/s E) 0.00 m/s

A

78) A ball is projected upward at time t = 0 s, from a point on a flat roof 10 m above the ground. The ball rises and then falls with insignificant air resistance, missing the roof, and strikes the ground. The initial velocity of the ball is 58.5 m/s. Consider all quantities as positive in the upward direction. At time t = 5.97 s, the vertical velocity of the ball is closest to A) 0 m/s. B) +175 m/s. C) +12 m/s. D) -175 m/s. E) -12 m/s.

A

79) A ball is projected upward at time t = 0 s, from a point on a flat roof 90 m above the ground. The ball rises and then falls with insignificant air resistance, missing the roof, and strikes the ground. The initial velocity of the ball is 80.5. Consider all quantities as positive in the upward direction. The vertical velocity of the ball when it is 89m above the ground is closest to A) -81 m/s. B) -64 m/s. C) -48 m/s. D) -32 m/s. E) -97 m/s.

C

8) A polar bear starts at the North Pole. It travels 1.0 km south, then 1.0 km east, and then 1.0 km north to return to its starting point. This trip takes 45 min. What was the bear's average speed? A) 0.00 km/h B) 0.067 km/h C) 4.0 km/h D) 5.3 km/h

E

80) A test rocket at ground level is fired straight up from rest with a net upward acceleration of 20 m/s2. After 4.0 s, the motor turns off but the rocket continues to coast upward with insignificant air resistance. What maximum elevation does the rocket reach? A) 160 m B) 330 m C) 320 m D) 410 m E) 490 m

A

81) A toy rocket is launched vertically from the ground level (y=0m), at time t=0.0 s. The rocket engine provides constant upward acceleration during the burn phase. At the instant of engine burnout, the rocket has risen to 59 m and acquired a velocity of 80 m/s. The rocket continues to rise in unpowered flight, reaches a max height, and falls back to the ground. The time interval, during which the rocket engine provides the upward acceleration, is closest to: A) 2.1 s. B) 2.3 s. C) 1.9 s. D) 1.7 s. E) 1.5 s.

A

82) A toy rocket is launched vertically from ground level (y=0m), at time t=0.0s. The rocket engine provides constant upward acceleration during the burn phase. At the instant of engine burnout, the rocket has risen 81m and acquired a velocity of 40m/s. The rocket continues to rise, reaches a max height, and falls to the ground. The upward acceleration of the rocket in the burn phase is closest to: A) 9.9 m/ . B) 9.6 m/ . C) 9.3 m/ . D) 9.0 m/ . E) 8.7 m/ .

A

83) A toy rocket is launched vertically from ground level (y = 0 m), at time t = 0.0 s. The rocket engine provides constant upward acceleration during the burn phase. At the instant of engine burnout, the rocket has risen to 49 m and acquired a velocity of 60 m/s. The rocket continues to rise in unpowered flight, reaches maximum height, and falls back to the ground. The maximum height reached by the rocket is closest to: A) 233 m. B) 221 m. C) 209 m. D) 244 m. E) 256 m.

E

84) A rock is projected upward from the surface of the Moon, at time t = 0 s, with an upward velocity of 30.0 m/s. The acceleration due to gravity at the surface of the Moon is 1.62 m/s2, and the Moon has no atmosphere. The height of the rock when it is descending with a speed of 20.0 m/s is closest to A) 115 m. B) 125 m. C) 135 m. D) 145 m. E) 154 m.

A

85)A ball is thrown straight upward from ground level with a speed of 18 m/s. How much time passes before the ball strikes the ground if we disregard air resistance? A) 3.7 s B) 1.8 s C) 1.1 s D) 0.6 s

B

89) An object is dropped from a bridge. A second object is thrown downwards 1.0 s later. They both reach the water 20 m below at the same instant. What was the initial speed of the second object? Neglect air resistance. A) 4.9 m/s B) 15 m/s C) 9.9 m/s D) 20 m/s E) 21 m/s

A

9) A polar bear starts at the North Pole. It travels 1.0 km south, then 1.0 km east, and then 1.0 km north to return to its starting point. This trip takes 45 min. What was the bear's average velocity? A) 0.00 km/h B) 0.067 km/h C) 4.0 km/h D) 5.3 km/h

C

90) To determine the height of a bridge above the water, a person drops a stone and measures the time it takes for it to hit the water. If the time is 2.3 s, what is the height of the bridge? Neglect air resistance. A) 10 m B) 14 m C) 26 m D) 32 m E) 52 m

C

91) To determine the height of a bridge above the water, a person drops a stone and measures the time it takes for it to hit the water. If the height of the bridge is 41 m, how long will it take for the stone to hit the water? Neglect air resistance. A) 2.3 s B) 2.6 s C) 2.9 s D) 3.2 s E) 3.6 s

D

92) An astronaut stands by the rim of a crater on the Moon, where the acceleration of gravity is 1.62 m/s2 and there is no air. To determine the depth of the crater, she drops a rock and measures the time it takes for it to hit the bottom. If the time is 6.3 s, what is the depth of the crater? A) 10 m B) 14 m C) 26 m D) 32 m E) 38 m

B

93) An astronaut stands by the rim of a crater on the Moon, where the acceleration of gravity is 1.62 m/s2 and there is no air. To determine the depth of the crater, she drops a rock and measures the time it takes for it to hit the bottom. If the depth of the crater is 120 m, how long does it take for the rock to fall to the bottom of the crater? A) 3.04 s B) 12.2 s C) 29.3 s D) 32.1 s E) 37.5 s

A

94) An object is thrown upwards with a speed of 16 m/s. How long does it take it to reach a height of 7.0 m on the way up? Neglect air resistance. A) 0.52 s B) 1.2 s C) 2.4 s D) 3.1 s E) 4.2 s

C

95) An object is thrown upwards with a speed of 13 m/s. How long does it take to reach a height of 4.0 m above the projection point while descending? Neglect air resistance. A) 0.42 s B) 1.2 s C) 2.3 s D) 3.1 s E) 4.2 s

A

96) To determine the height of a flagpole, Abby throws a ball straight up and times it. She sees that the ball goes by the top of the pole after 0.50 s and then reaches the top of the pole again after a total elapsed time of 4.1 s. How high is the pole above the point where the ball was launched? Neglect air resistance. A) 10 m B) 13 m C) 16 m D) 18 m E) 26 m

B

97) Abby throws a ball straight up and times it. She sees that the ball goes by the top of a flagpole after 0.50 s and reaches the level of the top of the pole after a total elapsed time of 4.1 s. What was the speed of the ball at launch? Neglect air resistance. A) 11 m/s B) 23 m/s C) 34 m/s D) 45 m/s E) 48 m/s

C

98) Abby throws a ball straight up and times it. She sees that the ball goes by the top of a flagpole after 0.50 s and reaches the level of the top of the pole after a total elapsed time of 4.1 s. What was the speed of the ball at as it passed the top of the flagpole? Neglect air resistance. A) 6.4 m/s B) 16 m/s C) 18 m/s D) 29 m/s E) 33 m/s