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lilmissbossy
Aug24-08, 09:33 PM
1. The problem statement, all variables and given/known data
force F is required to push a crate of mass m up a plank of length L into a truck whose platform is a vertical distance h above the road.

a)How much work is done pusing the crate up the plank m=100kg, L=5m, F=490N h=1.2m
b)what is the increase in PE of the crate once the crate is on the platform


2. Relevant equations
W=Fxd
PE=mgh



3. The attempt at a solution

ok so my working is

W=Fxd
W=490Nx5m
W=2450N

and

PE=mgh
PE=(100kg)(9.8ms-1)(1.2m)
PE=1176 N

Hmmmmmmm...........i think they are right

Defennder
Aug24-08, 11:45 PM
Yeah it looks ok, provided no friction is involved and F is directed along the length of L.

lilmissbossy
Aug24-08, 11:57 PM
Excellent i finally got one right by myself!!!