posted by Sarah .
A potter’s wheel with rotational inertia of 45 kg m2, is spinning freely at 40 rpm. The potter drops a lump of clay onto the wheel where it sticks a distance 1.2 m from the rotational axis at the wheel’s center. If the subsequent angular speed of the wheel is 32 rpm, what is the clay’s mass? (Hint: treat the clay as a point object, so I=mr2)