# Angular acceleration of a wheel

1. May 24, 2012

1. The problem statement, all variables and given/known data

What is the formula for angular acceleration, when the wheel's diameter, speed, acceleration and distance are known.

2. Relevant equations

3. The attempt at a solution

2. May 24, 2012

### spacelike

The hard part is realizing that the speed the wheel is moving at (I'm assuming it's a wheel attached to a moving body like a car driving on the road) is equal to the tangential speed of a particle on the end of the wheel. Same can be said about acceleration.

So, then you simply convert between tangential and angular values, you said diameter is known, so these are given in terms of diameter d (with d=2r) as
$$\alpha=\frac{2a_{t}}{d}$$, $$\omega=\frac{2v_{t}}{d}$$

3. May 24, 2012

### Staff: Mentor

Welcome to the PF.

You are asking for an equation for acceleration, when the acceleration is known?