Angular Accelaration = Angular Velocity^2 ?

1. Jan 6, 2010

makyol

Angular Accelaration = Angular Velocity^2 ???

1. The problem statement, all variables and given/known data
Can we always says angular accelaration is equal to angular velocity^2? My friend said that i was wrong when think like that to solve question?

2. Relevant equations
Accelaration = -(angular velocity)^2 X Radius

Acceleration = Radius X Angular Accelaration

3. The attempt at a solution
When i solve those two equations together i get what i hougt. Is there any problem with that? If any please let me know where? Thanks.

2. Jan 6, 2010

Staff: Mentor

Re: Angular Accelaration = Angular Velocity^2 ???

You are mixing up angular acceleration, centripetal acceleration, and tangential acceleration:
This relates centripetal acceleration to angular velocity:
Centripetal acceleration = ω²R

This relates tangential acceleration to angular acceleration:
Tangential acceleration = αR