Question

A grindstone of radius 4.0 m is initially spinning with an angular speed of 8.0 rad/s. The angular speed is then increased to 12 rad/s over the next 4.0 seconds. Assume that the angular acceleration is constant.What is the magnitude of the angular acceleration of the grindstone?

Answer 1

Answer:

$1 rad/s^2$

Explanation:

The magnitude of the constant angular acceleration is the change in angular velocity over a unit of time. So if the angular speed increases from 8 rad/s to 12 rad/s in 4 seconds then the angular acceleration is:

$\alpha = \frac{\Delta \omega}{\Delta t} = \frac{12 - 8}{4} = \frac{4}{4} = 1 rad/s^2$