Friction Force

[dorkee]

1. The problem statement, all variables and given/known data
A force of 105N is applied horizontally to a 20.0 kg box to move it across a horizontal floor. If the box has an acceleration of 3.00 m/s^2, find the coefficient friction.


2. Relevant equations
coefficient friction = Ff/Fn


3. The attempt at a solution
I converted the mass into newtons so 20.0 kg = 196 N
I have no idea how to do this. I drew a picture, but I don't know what to do with the acceleration.

[LowlyPion]

1. The problem statement, all variables and given/known data
A force of 105N is applied horizontally to a 20.0 kg box to move it across a horizontal floor. If the box has an acceleration of 3.00 m/s^2, find the coefficient friction.


2. Relevant equations
coefficient friction = Ff/Fn


3. The attempt at a solution
I converted the mass into newtons so 20.0 kg = 196 N
I have no idea how to do this. I drew a picture, but I don't know what to do with the acceleration.

Ok. What would the acceleration be if there was no friction?

Won't the difference then be how much friction has retarded its motion?