# Homework Help: What is the coefficient of friction?

1. Oct 10, 2011

### alisong

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

A 500kg box is being pushed across a floor, with an applied force of 8400N, at a constant velocity, at an angle of 35 degrees below the horizontal. What is the coefficient friction between the floor and the box.

2. Relevant equations

I really do not know where to start.

3. The attempt at a solution

I know that Ff= (coefficient of kinetic friction)*mass*gravity
and because it's at constant velocity Fp=Ff right?
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Oct 10, 2011

### 1MileCrash

You understand the most important part already.

It's also important to realize though, that the applied force magnitude does not equal friction force, but it is a component of applied force that equals friction force.

Also, we have a vertical component of the applied force that will effect your normal force.

Can you find the i and j components of this 8400N force applied at your 35* angle?