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Help with rotational dynamics

  • Thread starter Axel H
  • Start date
1
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1. Homework Statement

http://imageshack.us/photo/my-images/545/rotacion1.jpg/
Translation: Determinate, for the system of Fig. 10-39 the angular velocity of the disk and the linear velocity of m and m'. Calculate the tension in each string. Suposse that m = 600 g, m' = 500 g, M = 800 g, R = 8 cm and r = 6 cm.


2. Homework Equations



3. The Attempt at a Solution
The problem is I don't know to get the moment of inertia because I have the mass of one disk only.
 

Spinnor

Gold Member
2,091
289
I agree, it looks like you were not given enough information.

One could assume that M was for both discs, but you would still need to know the thicknesses of the two discs which you could estimate if you had to.

Bad problem.
 

ehild

Homework Helper
15,365
1,776
Solve the problem assuming that M is the mass of the whole pulley that consist of two disk-form parts of the same thickness, made of the same material. Usually the problem writers think in 2D where thickness does not exist.:wink:

ehild
 

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