# Friction force

1. Apr 30, 2010

### Angello90

Hi guys,

I got this thought in my head.

If I have a box of mass x, being pulled towards East and the angle $$\theta$$,
then force applied to the box in order to move it on the surface with friction coefficient $$\mu$$ has to be in such a way:

My question is... wouldn't N be:

Or, N would be as usual W but in opposite direction? The drawing shows all the forces on the box:

Cheers and thanks for the thought

#### Attached Files:

File size:
3.8 KB
Views:
144
File size:
20.7 KB
Views:
149
• ###### 3.jpg
File size:
3.8 KB
Views:
204
2. Apr 30, 2010

### Staff: Mentor

You got it.

Nope. You were right the first time. The key is that there must be no net force on the box in the vertical direction.

3. Apr 30, 2010

### Angello90

Ok thanks a mil! I was bit confused