# Homework Help: Forces on a cylinder?

1. Apr 1, 2012

### kjn11994

1. The problem statement, all variables and given/known data

A cloth tape is wound around the outside of a uniform solid cylinder (mass M, radius R) and fastened to the ceiling as shown in the diagram below. They cylinder is held with the tape vertical and then released from rest. as the cylinder descends, it unwinds from the tape without slipping. The moment of inertia of a uniform solid cylinder about its center is 1/2MR^2.

diagram: http://imgur.com/h0v07

what are the forces acting on the cylinder?

2. Relevant equations

3. The attempt at a solution

http://imgur.com/eyjPP

so far i'm pretty sure there should be tension in the tape, force of gravity, some torque and (mv^2)/r but I have no clue which directions they should go if they even apply

2. Apr 1, 2012

### Saitama

The question is asking about only forces, not torques.

3. Apr 2, 2012

### kjn11994

so then, would these be all of the forces?

http://imgur.com/ofZTp

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