Physics Chapter 2

A cheetah can run at approximately 100 km/hr and a gazelle at 80.0 km/hr. If both animals are running at full speed, with the gazelle 70.0 m ahead, how long before the cheetah catches its prey? A: 12.6 s B: 25.2 s C: 6.30 s D: 10.7 s E: 20.3 s

A: 12.6 s

A 50-g ball traveling at 25.0 m/s is bounced off a brick wall and rebounds at 22.0 m/s. A high-speed camera records this event. If the ball is in contact with the wall for 3.50 ms, what is the average acceleration of the ball during this time interval? A: 13400 m/s^2 B: 6720 m/s^2 C: 857 m/s^2 D: 20 m/s^2 E: 15 m/s^2

A: 13400 m/s^2

A rock, released at rest from the top of a tower, hits the ground after 1.5 s. What is the speed of the rock as it hits the ground? (g = 9.8 m/s2 and air resistance is negligible) A: 15 m/s B: 20 m/s C: 31 m/s D: 39 m/s E: 40 m/s

A: 15 m/s

A European sports car dealer claims that his car will accelerate at a constant rate from rest to 100 km/hr in 8.00 s. If so, what is the acceleration? (Hint: First convert speed to m/s.) A: 3.47 m/s^2 B: 6.82 m/s^2 C: 11.4 m/s^2 D: 17.4 m/s^2 E: 19.5 m/s^2

A: 3.47 m/s^2

Mt. Everest is more than 8 000 m high. How fast would an object be moving if it could free fall to sea level after being released from an 8000-m elevation? (Ignore air resistance.) A: 396 m/s B: 120 m/s C: 1200 m/s D: 12000 m/s E: 521 m/s

A: 396 m/s

A truck moves 70 m east, then moves 120 m west, and finally moves east again a distance of 90 m. If east is chosen as the positive direction, what is the truck's resultant displacement? A: 40 m B: -40 m C: 280 m D: -280 m E: 230 m

A: 40 m

A parachutist jumps out of an airplane and accelerates with gravity to a maximum velocity of 58.8 m/s in 6.00 seconds. She then pulls the parachute cord and after a 4.00-second constant deceleration, descends at 10.0 m/s for 60.0 seconds, reaching the ground. From what height did the parachutist jump? A: 914 m B: 1130 m C: 1520 m D: 1750 m E: 1820 m

A: 914 m

A baseball is released at rest from the top of the Washington Monument. It hits the ground after falling for 6.0 s. What was the height from which the ball was dropped? (g = 9.8 m/s2 and assume air resistance is negligible) A: 1.5 x 10^2 m B: 1.8 x 10^2 m C: 1.1 x 10^2 m D: 2.1 x 10^2 m E: 2.5 x 10^2 m

B: 1.8 x 10^2 m

A cheetah can maintain its maximum speed of 100 km/hr for 30.0 seconds. What minimum distance must a gazelle running 80.0 km/hr be ahead of the cheetah to escape? A: 100 m B: 167 m C: 70.0 m D: 83.0 m E: 184 m

B: 167 m

The distance of the Earth from the sun is 93 000 000 miles. If there are 3.15 ´ 107 s in one year, find the speed of the Earth in its orbit about the sun. A: 9.28 miles/s B: 18.6 miles/s C: 27.9 miles/s D: 37.2 miles/s E: 41.3 miles/s

B: 18.6 miles/s

A bird, accelerating from rest at a constant rate, experiences a displacement of 28 m in 11 s. What is the average velocity? A: 1.7 m/s B: 2.5 m/s C: 3.4 m/s D: 4.2 m/s E: zero

B: 2.5 m/s

John throws a rock down with speed 14 m/s from the top of a 30-m tower. If g = 9.8 m/s2 and air resistance is negligible, what is the rock's speed just as it hits the ground? A: 12 m/s B: 28 m/s C: 39 m/s D: 350 m/s E: 784 m/s

B: 28 m/s

Maria throws two stones from the top edge of a building with a speed of 20 m/s. She throws one straight down and the other straight up. The first one hits the street in a time t1. How much later is it before the second stone hits? A: 5 s B: 4 s C: 3 s D: 2 s E: Not enough information is given to work this problem

B: 4 s

A rock is thrown straight down with an initial velocity of 14.5 m/s from a cliff. What is the rock's displacement after 2.0 s? (Acceleration due to gravity is 9.80 m/s2.) A: 28 m B: 29 m C: 55 m D: 64 m E: 72 m

B: 49 m

A drag racer starts from rest and accelerates at 10 m/s2 for the entire distance of 400 m (1/4 mile). What is the velocity of the race car at the end of the run? A: 45 m/s B: 89 m/s C: 130 m/s D: 180 m/s E: 210 m/s

B: 89 m/s

A ball is thrown vertically upwards at 19.6 m/s. For its complete trip (up and back down to the starting position), its average speed is: A: 19.6 m/s B: 9.80 m/s C: 4.90 m/s D: 3.15 m/s E: not given

B: 9.80 m/s

Jeff throws a ball straight up. For which situation is the vertical velocity zero? A: On the way up B: At the top C: On the way back down D: Both A & C E: None of the above

B: At the top

Two objects of different mass are released simultaneously from the top of a 20-m tower and fall to the ground. If air resistance is negligible, which statement best applies? A: The greater mass hits the ground first B: Both objects hit the ground together C: The smaller mass hits the ground first D: No conclusion can be made with the information given

B: Both objects hit the ground together

An x vs. t graph is drawn for a ball moving in one direction. The graph starts at the origin and at t = 5 s the velocity of the ball is zero. We can be positive that at t = 5 s, A: The slope of the curve is non-zero B: The ball has stopped C: The acceleration is constant D: The curve is at x=0, t=0 E: The slope of the curve is zero

B: The ball has stopped

The slope of the acceleration vs. time curve represents: A: the velocity B: the rate of change of acceleration C: the rate of change of displacement D: the area under the position vs. time curve E: the area under the velocity vs time curve

B: the rate of change of acceleration

A change in a physical quantity w having initial value wi and final value wf is given by which of the following? A: wi-wf B: wf-wi C: (wf+wi)/2 D: (wf-wi)/2 E: none of the above

B: wf-wi

A vehicle designed to operate on a drag strip accelerates from zero to 30 m/s while undergoing a straight line path displacement of 45 m. What is the vehicle's acceleration if its value may be assumed to be constant? A: 2.0 m/s^2 B: 5.0 m/s^2 C: 10 m/s^2 D: 15 m/s^2 E: 17 m/s^2

C: 10 m/s^2

Omar throws a rock down with speed 12 m/s from the top of a tower. The rock hits the ground after 2.0 s. What is the height of the tower? (air resistance is negligible) A: 20 m B: 24 m C: 44 m D: 63 m E: 71 m

C: 44 m

A water rocket, launched from the ground, rises vertically with acceleration of 30 m/s2 for 1.0 s when it runs out of "fuel." Disregarding air resistance, how high will the rocket rise? A: 15 m B: 31 m C: 61 m D: 120 m E: 132 m

C: 61 m

A cart is given an initial velocity of 5.0 m/s and experiences a constant acceleration of 2.0 m/s2. What is the magnitude of the cart's displacement during the first 6.0 s of its motion? A: 10 m B: 55 m C: 66 m D: 80 m E: 97 m

C: 66 m

In the case of constant acceleration, the average velocity equals the instantaneous velocity: A: at the beginning of the time interval B: at the end of the time interval C: half-way through the time interval D: three-fourths of the way through the time interval E: one-fourth of the way through the time interval

C: half-way through the time interval

Changing the positive direction in a reference frame to the opposite direction does not change the sign of which of the following quantities? A: velocity B: average velocity C: speed D: displacement E: acceleration

C: speed

A strobe photograph shows equally spaced images of a car moving along a straight road. If the time intervals between images is constant, which of the following cannot be positive? A: the speed of the car B: the average velocity of the car C: the acceleration of the car D: the direction of motion of the car E: the instantaneous velocity of the car

C: the acceleration of the car

A strobe photograph of a car moving along a straight road shows the interval between each successive image to be diminishing. If the direction of motion of the car is taken as positive, which of the following are negative? A: The speed of the car B: the average velocity of the car C: the average acceleration of the car D: the instantaneous velocity of the car E: all of the above

C: the average acceleration of the car

A ball is pushed with an initial velocity of 4.0 m/s. The ball rolls down a hill with a constant acceleration of 1.6 m/s2. The ball reaches the bottom of the hill in 8.0 s. What is the ball's velocity at the bottom of the hill? A: 10 m/s B: 12 m/s C: 16 m/s D: 17 m/s E: 19 m/s

D: 17 m/s

When a drag strip vehicle reaches a velocity of 60 m/s, it begins a negative acceleration by releasing a drag chute and applying its brakes. While reducing its velocity back to zero, its acceleration along a straight line path is a constant -7.5 m/s2. What displacement does it undergo during this deceleration period? A: 40 m B: 80 m C: 160 m D: 240 m E: 310 m

D: 240 m

A rock is thrown straight up with an initial velocity of 24.5 m/s. What maximum height will the rock reach before starting to fall downward? (Take acceleration due to gravity as 9.80 m/s2.) A: 9.80 m B: 19.6 m C: 24.5 m D: 30.6 m E: 35.3 m

D: 30.6 m

In one-dimensional motion where the direction is indicated by a plus or minus sign, the average velocity of an object has which of the following properties? A: It is positive B: It is negative C: It is zero D: It can be positive, negative, or zero E: It isn't zero

D: It can be positive, negative, or zero