Joe pushes horizontally on a heavy box across a rough surface at constant speed. Which one of the following statements concerning this situation is false?
If Joe stops pushing on the box, the box will stop sliding eventually.
If Joe doubles his force on the box, the speed of the box will double.
The magnitude of the force of kinetic friction acting on the box must be equal to the magnitude of the force that Joe is applying to the box.
If the box were lighter, Joe could apply a smaller force to achieve the same constant speed.