# Pulley Problem

1. Apr 16, 2010

### ChrisMC

In the figure, m1 = 3.0 kg. Use work and energy to find the speed of the m2 = 1.7 kg block just before it hits the floor in each of the following cases.

http://www.webassign.net/knight/p11-48alt.gif

(a) The table is frictionless.
. m/s
(b) The coefficient of kinetic friction of the 3.0 kg block is 0.15.
m/s

F= mg
F= mg-Muk*n

2. Apr 16, 2010

### PhanthomJay

Chris

Please show some attempt at a solution using the requested work-energy approach. I would suggest using the conservation of total energy principle for each case.

3. Apr 16, 2010

### ChrisMC

I honestly dont know where to start, I thought if the mass on top was heavier than the mass hanging wouldnt move.

4. Apr 16, 2010

### PhanthomJay

well,no, on a frictionless surface, for example, the mass on the table could be enormous, but it would move with just the slightest force acting on it (the hanging mass could be therefore quite small). Are you familiar with the conservation of energy equations? Try writing them for the frictionless case, and then for the friction case.