Need A Little Assistance With Angular Velocity Problem?

Question

A 180 g, 31.0-cm-diameter turntable rotates on frictionless bearings at 61.0 rpm. A 16.0 g block sits at the center of the turntable. A compressed spring shoots the block radically outward along a frictionless groove in the surface of the turntable.

1) What is the turntable's rotation angular velocity when the block reaches the outer edge, in rpm's?

**I know that the answer is 51.8 rpm but i just don't know how to solve the problem and show the work to get that answer. If anyone could help me with that then that would be great and much appreciated.

Answer 1

use mwr = Iw and plugin values

how did you solve it?