How Fast Does the Rim of a Rotating Disk Move?

[05holtel]

Homework Statement

A thin, 100.0 g disk with a diameter of 8.00 cm rotates about an axis through its center with 0.150 J of kinetic energy.

What is the speed of a point on the rim?

The Attempt at a Solution

1/2mv^2 = 0.15
v = 1.73m/s

I know
Vt = angular velocity x r

I am not sure how to solve foe the angular velocity

 

[cashmoney805]

1/2 mv^2 = kinetic energy, correct. However, here you're dealing with rotational KE. You need a different formula. Does that help?