F * 4.2 = work done by friction
Ke at start = (1/2)(2.2)(5.5)^2
Ke at finsh = 0
chnge in potential energy = 0 because level
so
4.2 F = 1.1* 5.5^2
A dead dog of mass 2.2 kg and an initial speed of 5.5 m.s-1 slides along a rough horizontal surface and stops after travelling 4.2 m. calculate the frictional force between the dog and the surface (Think of the work the friction has to do to stop the dog – the Ek of the dog will be changed into heat energy by this work).
1 answer
1 answer