A little help , rotational and youngs modulus

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The discussion revolves around a physics problem involving a solid ball and a hollow ball on an incline, focusing on calculating the final tangential velocity and angular momentum after rolling 1 km. Key equations mentioned include the moment of inertia (I = mr^2), kinetic energy (KE = Iω^2 and KE = 1/2mv^2), and potential energy (PE = mgh). Participants clarify that the moments of inertia for both objects can be combined since they are about the same axis. Additionally, the relationship between linear velocity (v) and angular velocity (ω) is emphasized as crucial for solving the problem. The conversation highlights the importance of understanding rotational dynamics in this context.
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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
 
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Hi invisiblewar! :smile:

(have an omega: ω :wink:)
invisiblewar said:
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. :smile:

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


awesome thanks so much
 

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