Q. A 1200-kg frictionless roller coaster starts from rest at a height of 24 m. What is its kinetic energy when it goes over a hill that is 12 m high?
A radio-controlled car increases its kinetic energy from 4 J to 12 J over a distance of 2 m. What was the average net force on the car during this interval?
Valerie is able to do 1200 joules of work in 10 seconds. Brett is able to do 5000 joules of work in 50 seconds. Who is more powerful?
Which produces the larger impulse: a force of 6 N acting for 3 s or a force of 4 N acting for 5 s? Explain.
What impulse is needed to stop a 1400-kg car traveling at 25 m/s?
A coach is hitting pop flies to the outfielders. If the baseball (m = 145 g) stays in contact with the bat for 0.04 s and leaves the bat with a speed of 50 m/s, what is the average force acting on the ball?
A cue ball hits a stationary eight ball on a pool table. For which of the following systems is there a change in momentum during the collision? Explain why.
a. the cue ball b. the eight ball c. both balls