# Homework Help: Inclined Plane Force w/ Friction

1. Oct 11, 2009

### yankeekd25

1. The problem statement, all variables and given/known data
A mass of m = 11 kg is placed on incline plane with friction. A force with a magnitude of F = 59 Newtons is applied downward, perpendicular to the plane at all times. As the angle of the incline is increased from zero degrees it remains static until it reaches an angle of x = 56.7 degrees when it begins to slide. What is the coefficient of static friction for this situation?

I'm guessing that I sum up the forces as I would for a non-friction inclined plane problem, and then divide by the 59 N that they give you? Would I be assuming correctly?

2. Oct 11, 2009

### sArGe99

The normal reaction on the block due to the plane is not 59 N. Draw a complete FBD and you'll see. (Resolve the grav. force on the block into its sine and cosine components)

3. Oct 11, 2009

### yankeekd25

I believe the answer is .762. mg sin theta / 118, where 118 is the calculated normal force?