# Homework Help: Pulling A block with Friction

1. Feb 2, 2009

### DeltaIceman

1. The problem statement, all variables and given/known data
A 3.52 kg block located on a horizontal frictionless floor is pulled by a cord that exerts a force F=12.6N at an angle theta=31.0degrees above the horizontal. The floor has a coefficient of kinetic friction µk = 0.04, what is the magnitude of the frictional force on the block when the block is moving? There is a second part which is What is the magnitude of the acceleration of the block when friction is being considered? Although I think I am forgetting forumals or something. If someone can just send me along the right track I think I can figure it out. Thanks!

m = 3.52
F= 12.6
Theta = 31 degrees
µk = 0.04

2. Relevant equations

Sine and cosine functions.
µkFn= fk

3. The attempt at a solution

2. Feb 2, 2009

### LowlyPion

You mean you think you are missing F = ma?

(Less of course the correction you will need to make for the retarding force of friction.)