# Angular Acceleration and wheel revolution

• ecthelion4

## Homework Statement

A wheel accelerates from rest to 59 rad/s at a rate of 29 rad/s². How many revolutions the wheel turned while accelerating?

## The Attempt at a Solution

I'm confused, I suck at this kind of problem. I got change in angular velocity which would be 59rad/s, and I got that the angular acceleration would be 29 rad/s². What equation relates all three? All equations I know relate them using time, but I got no time there.

The equation you are looking for is an EXACT analog of the equation for linear motion, s=(1/2)*a*t^2. Does that help?

Not really. See that would translate into angular motion as this:

Angular Displacement = 1/2*Angular Acceleration*Time²

And since I got no time, that equation is useless. I need an equation that somehow relates ONLY angular displacement to angular velocity and angular acceleration

Unless I'm missing a way to get the time from the given data...

Well, you know the initial velocity, the final velocity and the acceleration. Could that give you a time?

...could it?

I would say that if I accelerate from 0 to 10 m/sec at an acceleration of 10 m/sec^2, then the time it takes is 1 sec.