A box is pushed horizontally with constant speed across a rough horizontal surface. Which of the following must be true?
a) The friction is less than the applied force
b) There is no friction acting on the box
c) The friction is greater than the applied force
d) The friction is equal to the applied force
Because if an object is moving at a constant speed the force of friction must equal the applied (horizontal) force, and for it to be accelerating or decelerating, the force of friction and the applied force must be unequal
