Exam 2: Motion in One Dimension

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?

The equation sf = si + vis Δt + as (Δt)² is valid for all types of motion because it is a fundamental equation of physics.

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?

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:

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?

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 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 acceleration to the original velocity?

Two identical objects A and B fall from rest from different heights to the ground.If object B takes twice as long as A to reach the ground,what is the ratio of the heights from which A and B fell? Neglect air resistance.

You go on a long trip and try to determine your average velocity by using the miles on your car's tripometer and the time the trip required.Why would the answer using this information most likely not be correct?

It is physically impossible for an object to have a negative acceleration and yet be speeding up.

The motions of a car and a truck along a straight road are represented by the velocity-time graphs below.The two vehicles are initially alongside each other at time t = 0. At time T,what is true of the distances traveled by the vehicles since time t = 0?

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:

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 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. )