# Finding the Coefficiant of friction

1. Nov 16, 2009

### BlakcDahlia

A cart that weighs 1.5 kg is accelerating at .12 M/s^2 on a horizontal surface. The cart is being pulled by a weight of 50 grams. Find the coefficiant of friction.

I've been using F=ma so 1.5(.12)=.18N

the weight pulling is equal to .05kg(9.8)=.49N

.49-.18=.31N=Ff Ff=m(Fn) .31=m(1500) m (the coefficient of friction)= .0002

I dont feel like this is the right answer, can anyone see what I'm doing wrong?

2. Nov 16, 2009

### rakbarut

Check your calculation for the normal force...Where did you get 1500 from?

3. Nov 16, 2009

### BlakcDahlia

I thought in Normal force was measured in grams, not kilograms. That may be where I went wrong. So the proper equation should be .31/1.5=.2? That seems pretty simple and for some reason feel like I've messed up somewhere else but if that's all that I seem to have done wrong then thanks!

4. Nov 16, 2009

### rakbarut

Again make sure all your calculations are correct...If the Ff = .31 N and the mass of the object is 1.5 kg use the equation µmg=Ff to solve for µ. I think you understand the concepts, just make sure you are doing the algebra correctly...

5. Nov 17, 2009

### Redbelly98

Staff Emeritus
Forces are measured in Newtons. Grams and kilograms are used for mass, not force.