A train brakes from 40 ms to a stop over a distance of 100 m. a)What is the acceleration of the train?
b)How much time does it take the train to stop?

How much work would be needed to raise the payload from the surface of the moon (i. e., x = r) to an altitude of 5r miles above the surface of the moon (i. e., x = 6r)?

What is the force that opposes motion and works against the downward pull? a) friction b) gravity c) weight d) acceleration

A1-lb collar is attached to a spring and slides without friction along a circular rod in a vertical plane. the spring has an undeformed length of 5 in. and a constant k =25 lb/ft. knowing that the collar is released from being held at a determine, the speed of the collar and the normal force between the collar and the rod as the collar passes through b.