# Eraser sliding down slope - Friction

1. Jun 1, 2005

### Kamataat

An eraser slides down a slope of height 1m that makes an angle of 35 degrees with the ground. It takes the eraser 1,8s to do this. Find the coefficient of friction.

I have no clue how to do this. I've not been able to solve any of the equations I've tried, because there is always the mass of the eraser which I don't know.

- Kamataat

2. Jun 1, 2005

### SpaceTiger

Staff Emeritus
Start by identifying the forces in the problem. What are they? What is their magnitude? What about their direction?

3. Jun 1, 2005

### brewnog

Just call the eraser's mass 'm', it should take care of itself.

4. Jun 3, 2005

### Kamataat

What am I supposed to do with the given time?

The forces are gravity, friction and the normal force?

- Kamataat

5. Jun 3, 2005

### Pyrrhus

The forces are constant, and do not change throught time, so the acceleration will be constant, you can use the uniform acceleration equations with the time. Notice you can calulate the distance covered.

6. Jun 4, 2005

### Kamataat

figured it out. thanks!!!!!!

- Kamataat