calculate the friction force of an object? if weight=19600,vi=30ms-1,vf=0ms-1 and S=100m.
If it is sliding to a stop along a horizontal surface, the initial kinetic energy equals the work done against friction. I will assume the weight is in Newtons
(M/2)Vi^2 = Ff*S
M = (19600 N)/g = 2000 kg
Ff = friction force = 1000*900/100
= 9000 N