Forces

When the forces of an object produce a net force of 0 N, the forces are balanced. When the force of an object is not 0 N, the forces on the object are unbalanced.

An applied force is a force that is applied to an object by a person or another object

The force of gravity is the force with which the earth, moon, or other massively large object attracts another object towards itself. By definition, this is the weight of the object.

The normal force is the support force exerted upon an object that is in contact with another stable object.

The friction force is the force exerted by a surface as an object moves across it or makes an effort to move across it.

The air resistance is a special type of frictional force that acts upon objects as they travel through the air.

The tension force is the force that is transmitted through a string, rope, cable or wire when it is pulled tight by forces acting from opposite ends.

The spring force is the force exerted by a compressed or stretched spring upon any object that is attached to it.

In water, if something has a greater density than the water, then it will sink. The opposite is also true.