posted by Mischa .
A worker pushes a 1500 N crate with a horizontal force of 345 N a distance of 24 m. Assume the coefficient of kinetic friction between the crate and the floor is .220. How much work is done by the floor on the crate?
Mg = 1500 N
mu,k = 0.220
X = 24 m
It is negative because the block's motion is in the opposite direction to the friction force exerted by the floor.