# Homework Help: Resultant forces on objects and springs

1. Aug 8, 2014

### slaw155

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

I've been struggling to work this out over the last week, so any help would be appreciated!

1: An object of mass 400kg is dragged at a constant velocity of 0.5m/s up a rough slope inclined at 25degrees to the horizontal. Given that coefficient of kinetic friction between object and ground = 0.75, at what rate is work done against friction?

2. Relevant equations

1: Power = work/time

3. The attempt at a solution

I haven't unfortunately gotten past knowing what equation to use :/

Last edited: Aug 8, 2014
2. Aug 8, 2014

### HallsofIvy

Have you drawn a picture with the individual force vectors?

3. Aug 8, 2014

### slaw155

I've tried for question 1 but don't know how to progress with it.

Last edited: Aug 8, 2014
4. Aug 8, 2014

### Simon Bridge

You don't need it. Part 2 is not even a force problem - try using energy conservation instead.