Finding the Coefficiant of friction

[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 don't feel like this is the right answer, can anyone see what I'm doing wrong?

 

[rakbarut]

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

 

[BlakcDahlia]

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

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!

 

[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...

 

[Redbelly98]

I thought in Normal force was measured in grams, not kilograms.

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