# Homework Help: Question concerning work

1. Oct 22, 2011

1. The problem statement, all variables and given/known data

*I already figured the problem out*

A luggage handler pulls a suitcase of mass 16.7 kg up a ramp inclined at an angle 30.0 degrees above the horizontal by a force $\overline{F}$ of magnitude 155 N that acts parallel to the ramp. The coefficient of kinetic friction between the ramp and the incline is 0.267. The suitcase travels a distance 4.10 m along the ramp.

A. Calculate the work done on the suitcase by the force F.
B. Calculate the work done on the suitcase by the gravitational force.
C. Calculate the work done on the suitcase by the normal force.
D. Calculate the work done on the suitcase by the friction force.
E. Calculate the total work done on the suitcase.

F. If the speed of the suitcase is zero at the bottom of the ramp, what is its speed after it has traveled 4.10 m along the ramp?

2. Relevant equations

F*s = Work

3. The attempt at a solution

A. Is it:
work of F applied= (155 N)(4.10 m)cos30.0 = 550.0 J

B. Is it
work of friction=(43.7 N)(4.10 m)cos180.0 = -179.0 J

C and D. Wouldn't both be 0, considering cos90 = 0?

E. Is it just 550 J + 0 J + 0 J + -179 J = 371 J?

F. No idea, need help.

Thoughts? Thanks!

Last edited: Oct 22, 2011
2. Oct 22, 2011

### Matterwave

s is along the ramp right? So, why are you projecting things to the horizontal direction?

3. Oct 22, 2011