Angular Velocity: Find Initial Velocity Given Acceleration & Displacement

[blaze33]

Homework Statement

a wheel rotates with a constant angular acceleration pie rad/s^2. during a certain time interval its angular displacement is pie rad. at the end of the interval its angular velocity is 2pie rad/s. what is the angular velocity at the beginning of the interval?

Homework Equations

tried looking at the angular velocity/displacement/acceleraions equations but i don't know how to even begin this question.

The Attempt at a Solution

well i have to find the initial angular velocity and the time interval is also unknown.

 

[rl.bhat]

In the problem angular acceleration, angular displacement and final velocity is given. Can you find an equation which contain initial velocity, final velocity, angular acceleration and angular displacement.

 

[blaze33]

yes but it also has time, which is uknown.

 

[jegues]

Lol at U of M exam questions ;). This one's simple, the key is constant acceleration.

w^2 = Wo^2 +2(alpha)(deltatheta) should do the trick ;)

 

[blaze33]

lol jegues thanks.
hope the exam will be simpler than that haha