8. A crate is being pushed across a rough floor surface. If no force is applied on the crate, the crate will slow down and come to a stop. If

the crate of mass 15 kg moving at speed 6 m/s comes to rest in 3 seconds, what is the rate at which the frictional force on the crate takes energy away from the crate? What is the coefficient of kinetic friction of the crate on the surface if it takes 9.0 m for the crate to come to rest? [4 pts]