Solve Maximum Speed Equation: I (of P) = I (of o) + Md*d

[dsptl]

http://img222.imageshack.us/img222/173/51254213vo1.jpg


attempt:

Our professor gave us this equation: I (of P) = I (of o) + Md*d, but i don't see a way tht i can find the answer by this equation

please Help!

 

[LowlyPion]

When the center of mass is at the bottom what is its change in potential energy?

Where did the PE go?

 

[dsptl]

When the center of mass is at the bottom what is its change in potential energy?

Where did the PE go?

so do i use energy conservation...

please tell me soon its due in an half our :(

 

[LowlyPion]

so do i use energy conservation...

please tell me soon its due in an half our :(

Why not use conservation of energy?

 

[dsptl]

Why not use conservation of energy?

huh?

 

[dsptl]

my 2nd trial:

I displaced= I shape axis + mR2

For the cylinder Ic is
Ic = 0.5 m R2

Ke= 0.5 I ω^2
the energy must be concerved when the center of rotation is changed from P to O.
We have
Ke(berore) =0.5 [0.5 m R2 + mR2] ω1^2 = 0.25[ 1+2] mR2ω1^2 = (3/4)mR2ω1^2
Ke(after) =0.5 [0.5 m R2 ] ω2^2 = (1/4) mR2ω2^2 we have

(3/4)mR2ω1^2 = (1/4) mR2ω2^2
ω2= √[(3/4)mR2ω1^2 /(1/4) mR2 ]=ω1√ 3

ω2= ω1√ 3


now tell me whts wrong here...i am not getting any value for ans??