M Prep | MCAT 2015 Question of the Day - Prep, Practice Questions, and More!

Q:	Imagine someone slides a large box of books down an inclined plane. The box slides the whole length of the plane at a constant velocity. This occurs because:

the static frictional force opposing the motion of the box equals the gravitational force down the plane.

the kinetic frictional force acting on the box and the gravitational force down the plane cancel one another.

the box's mass is not sufficient to accelerate the box down the inclined plane.

both the box and the inclined plane are frictionless.