A little help , rotational and youngs modulus

[invisiblewar]

A little help please, rotational and youngs modulus

Homework Statement

A solid Ball with a mass of 3kg and r=1m is suspended in the center of a hollow ball of mass=1kg and r=3m. It is placed at rest on a 33 degree incline. after rolling 1km along the incline what's the final tangetial velocity? what's the objects final angular momentum?

Homework Equations

I know i need I=mr^2
and I am pretty sure this is a conservative problem so KEi+PEi=KEf+PEf
KE=Iw^2 and KE=1/2mv^2
PE=mgh or mgr

The Attempt at a Solution

Im not too sure how to input the problem at all...should I combine the two moments of Inertia? then go from there or should they both be done seperately? This problem is killing me

thanks in advance everyone

 

[tiny-tim]

Hi invisiblewar!

(have an omega: ω )

Im not too sure how to input the problem at all...should I combine the two moments of Inertia? then go from there or should they both be done seperately?

Yes, moments of inertia (about the same axis) are scalars, so you just add them.

(and it's rolling, so don't forget to find the equation relating v to ω )

 

[invisiblewar]

awesome thanks so much