Okay I kind of get this problem but not completey. Please see if I'm going in the right direction and guide me through it. Thanks!!(adsbygoogle = window.adsbygoogle || []).push({});

Here is the Problem: A 5kg block is pushed 3m up a vertical wall with constant speed by a constant force of magnitude F applied at an angle of theta=30 degrees with the horizontal. If the coefficient of kinetic friction between block and wall is 0.30, determine the work done by a) F, b) the force of gravity, and c) the normal force between block and wall. d) By how much does the gravitational potential energy increase during this motion?

Here is my work:

First of all I solved for the F force and I got 208 N

So then do I have to plug the force into the equation: W=Fcos(theta)(displacement) ??

Then it would be: 208cos30(3m) right??

For b) you need to find the work force of gravity.

So, W=(9.8m/s^2)cos180(3m)??

for c) normal force between block and wall.

would it be zero?? because the block moves upward and the normal force would be perpendicular to the displacement.

for d) How do you find how much the gravitational potential energy increases by? Do you use Usubi+Ksubi=Usubf+Usuf

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Work done by forces

**Physics Forums | Science Articles, Homework Help, Discussion**