# Friction of rubber box on concrete floor

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1. Feb 15, 2017

### anon3005

1. The problem statement, all variables and given/known data
A 10 kg rubber box is resting on a concrete floor. A force of 200 N is then applied to this box in a horizontal direction. What is the magnitude of the friction force on the box?

2. Relevant equations
This is a question about applying newton's laws so Fsmax = μs η and η = mg.

3. The attempt at a solution
I have had answers -200 N, 98.1N, and 200N in which they are all incorrect. I have an idea it could be 0 N since the net force would have to be 0 since it is at rest and there is a static friction present but I am not sure.

2. Feb 15, 2017

### cnh1995

What is the co-efficient of friction between rubber and concrete? Is that given? If not, I think you should look it up.

3. Feb 15, 2017

### anon3005

It's 1.00

4. Feb 15, 2017

### cnh1995

So what's the equation?

5. Feb 17, 2017

### James R

Is the question asking about the friction force before it starts sliding, or after (assuming it slides)?

6. Feb 17, 2017

### haruspex

Given the coefficient of friction, it is safe to assume it slides.