Physics Set (2)

A sports car can go from rest to 32 m/s in 3.88 s. The same car can come to a full stop from that speed in 3.96 s. What is the ratio of starting to stopping accelerations?

-1.0

A ball is projected upward at time t = 0.0 s, from a point on a roof 60 m above the ground. The ball rises, then falls and strikes the ground. The initial velocity of the ball is 28.4 m/s. Consider all quantities as positive in the upward direction. At time t = 4.3 s, the acceleration of the ball is closest to:

-10 m/s^2

A ball is projected upward at time t = 0.0 s, from a point on a roof 90 m above the ground. The ball rises, then falls and strikes the ground. The initial velocity of the ball is 80.5 m/s. Consider all quantities as positive in the upward direction. The velocity of the ball when it is 89 m above the ground is closest to:

-81 m/s

At the same moment, one rock is dropped and one is thrown downward with an initial velocity of 10 m/s from the top of a 300 m building. How much earlier does the thrown rock strike the ground? (Disregard air resistance.)

0.95s

A package is dropped from a helicopter moving upward at 15 m/s. If it takes 16.0 s before the package strikes the ground, how high above the ground was the package when it was released? (Disregard air resistance.)

1000m

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 64 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 time interval, during which the rocket engine provides upward acceleration, is closest to:

2.1s

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:

233m

A dragster travels 1/4 mi in 6.7 s. Assuming that acceleration is constant and the dragster is initially at rest, what is its velocity when it crosses the finish line?

269 mi/hr

A racquetball strikes a wall with a speed of 30 m/s and rebounds with a speed of 26 m/s. The collision takes 20 ms. What is the average acceleration of the ball during the collision?

2800 m/s^2

A bicyclist starts a timed race at 6.0 mi/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?

36mi/h

A test rocket is fired straight up from rest with a net acceleration of 20 m/s2. After 4 seconds the motor turns off, but the rocket continues to coast upward. What maximum elevation does the rocket reach?

487m

Human reaction times are worsened by alcohol. How much farther would a drunk driver's car travel before he hits the brakes than a sober driver's car? Assume both cars are initially traveling at 49.0 mi/h, the sober driver takes .33 s, and the drunk driver takes 1.0 s to hit the brakes in a crisis.

48ft

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?

60mph

) A car moving at a velocity of 20 m/s is behind a truck moving at a constant velocity of 18 m/s. When the car is 50 m behind the front of the truck, the car accelerates uniformly at 1.8 m/s2. The car continues at the same acceleration until it reaches a velocity of 25 m/s, which is the legal speed limit. The car then continues at a constant velocity of 25 m/s, until it passes the front of the truck. The distance the car travels while accelerating, in meters, is closest to:

62

A ball is thrown straight upward with a velocity of 39 m/s. How much time passes before the ball strikes the ground? (Disregard air resistance.)

8.0s

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 81 m and acquired a velocity of 40 m/s. The rocket continues to rise in unpowered flight, reaches maximum height, and falls back to the ground. The upward acceleration of the rocket during the burn phase is closest to:

9.9m/s^2