Resultant forces on objects and springs

[slaw155]

Homework Statement

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?

Homework Equations

1: Power = work/time

The Attempt at a Solution

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

 

[HallsofIvy]

Have you drawn a picture with the individual force vectors?

 

[slaw155]

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

 

[Simon Bridge]

I've tried for question 1 but for question 2 I can't figure out how we can find the extra force exerted on the spring when the mass is pushed down on it (this force is additional to the weight of the object)

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