Moment of inertia and angular acceleration

1. Mar 13, 2013

physicssss

1. The problem statement, all variables and given/known data
If the fall height of the mass is doubled, the angular acceleration of the wheel will
a. decrease by an unkown amount
b. remain unchanged
c. decrease by a factor of 2
d. increase by an unknown amount
e. increase by a factor of 2

2. Relevant equations

3. The attempt at a solution
well since angular acceleration is slope of linear graph and if we double the height(x-axis) I think the angular frequency will remain constant. But maybe I'm wrong. That is why I need help.

2. Mar 13, 2013

Simon Bridge

The description is not complete.
Fall of what and how is this related to a wheel?

Is this a mass falls onto a wheel, where it stays somehow, and so makes it turn?
Hint: conservation of energy.

3. Mar 14, 2013

physicssss

its a suspended mass attached to to the hub of a bicycle wheel through a pulley. so basically we release the wheel (which is attached to a table) and it turns from the weight of the suspended mass until the mass reaches the floor.
Anyways I have come to a new conclusion that the angular acceleration doubles from the height being double.
I still need confirmation though.

4. Mar 14, 2013

Simon Bridge

Yeh - the final speed is higher, but the time is also longer.
You need to use the kinematic equations for rotating bodies or conservation of energy if you want a mathematical approach - or you can use your understanding of gravity.

If the mass were free to just fall - not attached to the wheel - how would the acceleration be affected by the distance it has to fall?