# Friction Force exerted on an object

1. Dec 10, 2015

### RaeZ

1. The problem statement, all variables and given/known data
A man is exerting a force of 200 N on a refrigerator and pushing the fridge across a rough floor at a constant velocity to the right.
How much friction force acts on the refrigerator ? Give a number and appropriate units.

2. Relevant equations
none

3. The attempt at a solution
I think that the friction force exerted by the floor would be equal to the man's exerted force on the refrigerator, but at the same time I know that the force exerted by the man and the friction force exerted by the floor are not an action/reaction pair, so I am not sure that they would be equal.

2. Dec 10, 2015

### Staff: Mentor

Action-reaction pairs have nothing to do with the answer to this problem. Have you drawn a free body diagram on the refrigerator, showing the horizontal forces acting on it?

Chet

3. Dec 10, 2015

### RaeZ

I was given a diagram (below) and told the force exerted by the man on the refrigerator is 200 N. In this case the man is A and the refrigerator is B

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4. Dec 10, 2015

### Staff: Mentor

Who says that forces that are not action-reaction pairs can't be equal? I still don't see your free body diagram showing only the refrigerator, with the forces acting on it.

5. Dec 10, 2015

### RaeZ

If I know that there is no acceleration, can I use Newton's second law to conclude that the friction force is equal to the force enacted upon the fridge by the man?

6. Dec 10, 2015

### Staff: Mentor

Sure

7. Dec 10, 2015

Thank you!!