WJEC M1 Jan 07 - Probably very Simple!

5/. A body, of mass 80kg slides in a straight line with constant deceleration across the horizontal surface on an ice rink. It's initial speed is 9ms(-1) and the body travels 75m before coming to rest.

a). Calculate Magnitude of deceleration of the body = 0.54 ms(-2)
b). Find time until body comes to rest = 50/3 seconds.

c). (This is the part I'm not sure about) - Assuming that the frictional force is the only force acting on the body that has a horizontal componont, calculate the coefficient of friction between the body and the surface of the ice rink.

I'm guessing that because the body is slowing down, it is limiting friction. The reaction of the ice rink on the body will be 80gN. Limiting friction is therefore uR = u(80g).

But I'm not too sure what to do next.