# Angular acceleration and angular velocity

## Homework Statement

Calculate the angular acceleration and angular velocity of a 4 kg object rotating in a circle of 3 m radius in a time of 6 s.

## The Attempt at a Solution

Angular acceleration = ω2*r

C=2∏r= 2*3.14*3=18.84

Angular acceleration= (2.09)2*3=12.54???????

Angular velocity= angular displacement/time ????

I just want to check whether my working is correct or not.

Nope.Its not right.

Remember, angular acceleration is dw/dt.

The acceleration w^2*r is centripetal accelwration.

Infact writing angular acceleration as w^2*r is dimemsionally inconsistent.

As nothing had been told about how w changes with time nothing can be said about angular acceleration.

In such cases w is assumed to be constant making angular acceleration 0

angular acceleration = 0

tiny-tim