Answer: K/2
Rotational kinetic energy can be expressed as: k (rotational) = 1/2 Iw2
where w is the angular velocity, I is
the moment of inertia around the axis of rotation.
K=1/2mv2
Kdrum=1/2 Iw2=1/2(1/2mR2) (v/R)2 =1/4 mv2 = 1/2K or K/2
The energy due to the rotation of an object and is part of its total kinetic energy is called rotational kinetic energy. Things that spool without sliding have some fraction of their energy as translational kinetic and the remainder as rotational kinetic and looking at rotational energy separately around an object’s axis of rotation yields the ratio that depends on the moment of inertia of the object that is rolling.
