A pulley with a radius of 3.0 cm and a rotational inertia of 4.5 *10^-3 kg.m² is suspended from the ceiling.A rope passes over it with a 2.0-kg block attached to one end and a 4.0-kg block attached to the other.The rope does not slip on the pulley.At any instant after the blocks start moving the object with the greatest kinetic energy is: A)the heavier block B)the lighter block C)the pulley D)either block (the two blocks have the same kinetic energy) E)none (all three objects have the same kinetic energy)

Question

Quizplus · Accepted Answer

The pulley has the greatest rotational kinetic energy, which is given by 1/2 I w^2, where I is the rotational inertia and w is the angular velocity. The pulley has the greatest rotational inertia, so it will have the greatest rotational kinetic energy.

A Pulley with a Radius of 3