Question

Abody in uniform horizontal circular motion possesses a variable velocity. Does it mean the kinetic energy of the body is variable.

Answer 1

In a uniform circular motion the speed of the body remains constant. If a body of mass ‘m’ moves in a circular path of radius ‘r’ and its angular velocity is ‘ω’ (which remain constant in uniform circular motion) the rotational kinetic energy is given by,

KE = ½ Iω²

Where, I is the moment of inertia of the body about the axis of rotation and I = mr².

So, KE = ½ mr²ω²

Which remains constant in uniform circular motion.