A classmate is attempting to draw a free body diagram for a box being pushed across the floor at a constant speed. The image below is what they have drawn so far.
Which (if any) of their forces have been drawn incorrectly?
A. The applied force should be the same size as the friction force.
B. There is nothing wrong with the free body diagram.
C. The normal force should be larger than the force of gravity.
D. The friction force should be in the same direction as the applied force.