Year 12s: what will be the first way you research your future options? >>

Physics coursework: finding the coefficient of friction

Hi guys!

well basically im doing A2 salters physics.. and I'm trying to measure the coefficient of friction between a shoe and different surfaces. I'm measuring static and dynamic coefficients of friction.

So for dynamic I will obviously have to give the shoe a PUSH, to make it go. HOWEVER I want that push to be of an exact force through out the whole experiment. The only two things that will vary is the normal reaction (weight of the shoe and masses I put on it) and the force which is needed to make it move. so what instrument can i use to make sure the force is alwys the same...

also... why does the velocity need to be consistent through out the experiment. I'm using dataloger to make sure its consistant, but for explaining purposes why?