# Coplanar equilibrium (mechanics)

1. Nov 3, 2007

### kring_c14

2. Nov 3, 2007

Since you have a free body diagram in the picture, you should have an idea of where to start.

3. Nov 3, 2007

### kring_c14

uhmmm, thats the problem..im really not that familiar with moments and stuff.. could you give me a hint???? plsssss...

4. Nov 3, 2007

OK, which forces are acting on the roller?

5. Nov 3, 2007

### kring_c14

well what I did was this one$$\sum Fx= Pcos20-Nsin20-Fsin70=0$$
$$\sum Fy=P sin20+Ncos20-Fcos70-120=0$$

then, i dont know what to do...

6. Nov 3, 2007

If the x-axis is along the incline (which is visible from the FBD), the your equations are not correct.

7. Nov 3, 2007

### kring_c14

so how do I make it right?

8. Nov 3, 2007