A pulley with a radius of 5 cm and a moment of inertia of 1.5 kg*m2 is spinning with a radial velocity of 3 rad/s. What is the magnitude of the force that must be applied to the edge of the pulley in order to bring it to rest in 10 seconds?

Arailroad car collides with and sticks to an identical railroad car that is initially at rest. after the collision, the total kinetic energy of the two cars is a) the same as before. b) half as much as before. c) one third as much as before. d) one fourth as much as before. e) twice as much as before.