Question

a box is on an inclined plane not moving. someone touches it and it starts to slide down at a constant speed until it reaches the bottom. why did it not stop? (1 point) the force of gravity was increased by the force of the touch, and this increase did not end until the box reached the bottom. static friction was decreased by the force from the touch, and the box was able to move. the net force on the box before the touch was less than the net force after the touch. static friction was keeping the box in place, but once it was moving, kinetic friction was not enough to stop it.

Explanation:

Static friction holds an object at rest. When the box was touched and set in motion, it switched from static to kinetic friction. Kinetic friction is generally less than the maximum static friction. Since the forces acting on the box (like gravity - component along the incline) were enough to keep it moving against the lower - magnitude kinetic friction, it did not stop.

Answer:

Static friction was keeping the box in place, but once it was moving, kinetic friction was not enough to stop it.