Angular acceleration of a bar on a hinge

[mickellowery]

Homework Statement

A bar on a hinge starts from rest and rotates with $$\alpha$$=(10+6t) rad/s² t is in seconds. Determine the angle in radians the bar turns in the first 4 seconds.

Homework Equations

I'm a little stumped how to get this one started. I assume i need to get it from angular acceleration to angular displacement, but I'm not exactly sure how to do that. So do I have to integrate it with respect to time twice?

The Attempt at a Solution

 

[Chewy0087]

That's right. Remember to use constants of integration/ boundary conditions in general (although it should make no difference in this case).