Angular Acceleration Problem: Solving for 0.5 rad/s^2 in Fixed Axis Rotation

[physicnow]

I got this problem and I got the answer 0.5 rad/s^2, but it is not the right one. pls help me. thanks

At t=0 wheel rotating about a fixed axis at a constant angular acceleration has an angular velocity of 2 rad/s. Two seconds later it has turned 5 complete revolutions. What is the angular acceleration of this wheel.

 

[Dick]

What's an equation relating angular displacement with time under uniform angular acceleration? And if you want to know why your answer is wrong you'll have to post what you actually did.

 

[physicnow]

Thanks

I figured it out already.