A thin hoop with a radius of 10 cm and a mass of 3.0 kg is rotating about its center with an angular speed of 3.5 rad/s. What is its kinetic energy?
A)0.18 J
B)0.092 J
C)0.96 J
D)1.05 J
E)0.53 J

Question

Quizplus · Accepted Answer

Kinetic energy of a rotating hoop is given by (1/2) * I * w^2, where I is the moment of inertia and w is the angular speed. For a thin hoop, I = MR^2, where M is the mass and R is the radius. Plugging in the given values, we get:KE = (1/2) * (3.0 kg) * (0.1 m)^2 * (3.5 rad/s)^2 = 0.18 J

A Thin Hoop with a Radius of 10 Cm and a Mass