- #1

- 53

- 2

## Homework Statement

The vertical exercise wheel in a mouse cage is initially at rest, but can turn without friction around a horizontal axis through the center of the wheel. The wheel has a moment of inertia I=0.0004kg m

^{2}and radius R = 0.06m An extremely smart pet mouse of mass m = 0.03 kg runs across her cage with initial speed v = 2 m/s, jumps onto the edge of her exercise wheel, holds on tightly, and rotates together with the wheel.

- Determine the angular velocity of the "wheel plus mouse turning together" immediately after she jumps on.
- Determine the maximum height of the mouse as she rides the wheel.

## Homework Equations

## The Attempt at a Solution

I solved the first one and got 7.09 rad/s by:

L = Rmv = Iω

0.06*0.03*2 = (0.0004+0.03*0.06

^{2})ω

ω = 7.09 rad/s

However part 2, I can't wrap my head around. I have an answer packet, but it has already had a couple incorrect solutions in it so I'm not quick to trust it.

I tried 1/2Iω

^{2}= mgh

KE = 1/2(5.08E-4)(7.09)

^{2}= 0.03*9.81*h

where h is the maximum height and 0.03 kg is the mass of only the mouse because the wheel is a homogenous cylinder and has equal mass on all "sides".

I feel like I'm missing torque though.

Any ideas?

Thanks guys