# Forces and Pulleys of two blocks

1. Jul 30, 2009

### Cheddar

1. The problem statement, all variables and given/known data
Two blocks are connected by a rope that passes over a set of pulleys. One block has a weight of 412N and the other has a weight of 908N. The rope and the pulleys are massless and there is no friction. (a) What is the acceleration of the lighter block? (b) Suppose that the heavier block is removed, and a downward force of 908N is provided by someone pulling on the rope. Find the acceleration of the remaining block. (c) Why are the answers in (a) and (b) different?

2. Relevant equations
weight = mass * acceleration(gravity)

3. The attempt at a solution
So mass = 42.0 kg for the smaller black and mass = 92.7 kg for the larger block.
This is as far as I get.

2. Jul 30, 2009

### Pupil

***NOT AN EXPERT***

If I were you, I would draw a force diagrams for each block. These kinds of problems can get really confusing if you don't sort out what forces are going where.

3. Jul 30, 2009

### tiny-tim

Hi Cheddar!

Call the tension T, do two F = ma equations, one for each block, and then eliminate T.