While punting a football, a kicker rotates his leg about the hip joint. the moment of inertia of the leg is 3.75 kg m2 and its rotational kinetic energy is 175 j. what is the angular velocity of the leg?

Angular velocity is the rate of the change of angular displacement of a body that is in a circular motion. It is a vector quantity so it consists of a magnitude and direction. It is equal to the linear velocity divided by the radius of the circular motion. However, we are not given the linear velocity and the radius of the motion. We instead use the equation for the rotational kinetic energy. It is expressed as:

Rotational kinetic energy = Iω^2 / 2

where I is the inertia and ω is the angular velocity

175 = (3.75)ω^2 / 2
ω = 9.66 rad/s

The angular velocity of the motion is about 9.66 rad / s.