You are pushing a cart across the room, and the cart has wheels at the front and the back. Your hands are placed on top of the cart at the center (left to right) of the top edge, pushing horizontally. There is friction between the wheels and the floor.

Is the normal force between the floor and the front wheels greater than, smaller than, or equal to the normal force between the floor and the rear wheels?

(A) The force on the front wheels must be smaller than the force on the rear wheels.
(B) The force on the front wheels must be equal to the force on the rear wheels.
(C) The force on the front wheels must be greater than the force on the rear wheels.