A Light-Weight Potter's Wheel, Having a Moment of Inertia Of 24

Multiple Choice

A light-weight potter's wheel, having a moment of inertia of $24 \mathrm {~kg} \cdot \mathrm { m } ^ { 2 }$ is spinning freely at 40.0 rpm. The potter drops a small but dense lump of clay onto the wheel, where it sticks a distance 1.2 m from the rotational axis. If the subsequent angular speed of the wheel and clay is 32 rpm, what is the mass of the clay?

A) 4.2 kg
B) 2.8 kg
C) 3.7 kg
D) 4.6 kg