# Angular Velocity Question Help Needed!

1. May 29, 2013

### MeghanPfeif

1. The problem statement, all variables and given/known data
A dirtbike is being used to turn a merry-go-round with a 650 kg mass, and a radius of 2m, and can be treated as a rotating disk (I=1/2 MR^2). The dirtbike is applying a force of 3.00kN tangentially to the surface of the merry-go-round, in a continuous way.
a. If the merry-go-round were to be starting from rest, what would its angular velocity be after 4s?
b. After 4s, what is the angular displacement that has occurred, in radians?
c. What arc-length would be covered by the outer-most part of the merry-go-round?
d. What would the tangential velocity at the very edge of the merry-go-round be?

2. Relevant equations
KE= 1/2Iω^2

3. The attempt at a solution
Sitting at my desk in almost tears for 2 hours because I cannot figure anything out.

2. May 29, 2013

### Staff: Mentor

Welcome to the PF.

Is the situation that the dirtbike is fixed somehow, and only applying an accelerating torque to the disk? What are the equations relating torque to angular acceleration and the moment of inertia (MOI)?