# Work and friction

1. Oct 14, 2008

### colts2775

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

A father pushes horizontally on his daughter’s sled to move it up a snowy incline. If the sled moves up the hill with a constant velocity, how much work is done by the father in moving it from the bottom to the top of the hill? The angle is 15 degrees, the top of hill is 3.6 meters high, the mass of girl and sled is 35 kg, and the coefficient of kinetic friction is 0.20.

2. Relevant equations

3. The attempt at a solution

I know that you have to sum the x and y components, and I know the y component is W=mgh=(35kg)(9.8 m/s^2)(3.6 m), and I know the final answer is 2300 J but I don't know how to get there.
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Oct 14, 2008

### physics girl phd

Work relates to the force parallel to the motion. Find that force first (i.e. turn the problem into a 1-d problem). Then find the distance of the motion. in this problem, it's easier that way... the motion is in a straight line against a constant force (caused by gravity in part and friction in part).