When two equal forces act in opposite directions the result is that the forces are balanced and there is no motion.

The process of moving or changing position.

When one force is stronger than the other the result is motion.

The amount of force that is applied to an object.

A force that attracts objects toward the earth. "What goes up, must come down!"

an object at rest tends to stay at rest, and an object in motion tends to stay in motion, with the same direction and speed.

for every action (force) there is an equal and opposite reaction (force).

the international unit of measure for force.