PLEASE HELP! A crate of mass 100 kg is being pushed in a straight line
across a horizontal floor at a constant speed of 4.0 m/s.
The coefficient of kinetic friction between the crate and
the floor is 0.3. Find the net force on the crate.
A. 0 N
B. 300 N
C. 400 N
D. 1200 N