# Weight and counterweight

1. Sep 2, 2014

### bobie

If two weights (Edit: hanging 10m above ground) on a frictionless pulley are equal (10kg) they will rest. If one is even slightly heavier (10.1kg) it will start to fall lifting up the other.

Is final velocity dependent on the difference of weight, or it will the same as if there is no counterweight?

Last edited: Sep 2, 2014
2. Sep 2, 2014

### A.T.

What do you think?

3. Sep 2, 2014

### dean barry

The final velocity is infinite, the acceleration rate of the system is the dependent, the root equation :
f = m * a

4. Sep 2, 2014

### Staff: Mentor

Are you familiar with free body diagrams? If so, then draw one for each weight, use that to help you write two equations in two unknowns. Then solve.

5. Sep 2, 2014

### A.T.

I assume that "final" is when the counterweight hits the pulley.

Or use energy conservation to see if the velocity is the same.

6. Sep 2, 2014

### Staff: Mentor

Excellent suggestion, that is even easier than my approach.