# Static friction and kinetic friction

1. Apr 21, 2013

### salmacho

A chuck is sliding downward an inclined plane with friction. The inclined plane has an angel 26 degrees with the horisontal. At a point the chuck has a velocity 4 m/s. The velocity after 2 seconds goes down to 2 m/s. The g is applied to 9.81 m/s^2.

So from here I need to find the kinetic and static friction. The problem for me is that I dont know where to start. When I try do find Fx and Fy, I need the mass, so which way should I go through?

Thanks! :)

2. Apr 21, 2013

### Staff: Mentor

You won't need the actual mass. Just call it "m" and continue.

What does the problem ask you to find? The coefficient of kinetic friction?

3. Apr 21, 2013

### salmacho

The problem wants me to find the coefficient between the chuck and the inclined plane

4. Apr 21, 2013

### Staff: Mentor

Good.

(1) Figure out the acceleration.

(2) Draw a free body diagram and then apply Newton's 2nd law.

5. Apr 21, 2013

### salmacho

6. Apr 21, 2013

### salmacho

7. Apr 21, 2013

### Staff: Mentor

Redo your algebra. You dropped a factor of g.

8. Apr 21, 2013

### jambaugh

salmacho,
Please, when you get a chance, read the guidelines for posting homework questions and use the template.