Unbalanced Forces

Two forces that are not exactly opposite in direction and/or equal in magnitude are unbalanced forces. What if you push on a wall or a heavy door and it does move? That would be an example of unbalanced forces.

If either the magnitude of the forces or direction of forces are not exactly opposite, then the forces are unbalanced. Unbalanced forces change the motion of the object being acted upon. An unbalanced force can make a stationary object move. It can also change the movement of an object already in motion, by causing it to speed up, slow down, or change direction.

The size and weight of the object a force is being applied to also determines how or if a certain force will be able to move it. The same unbalanced force will move an object with more mass more slowly than an object with less mass.

For example, if you kick a soccer ball, you are exerting an unbalanced force on the ball. The unbalanced force acts on the ball and makes it move.

If you kicked a heavy boulder instead of a soccer ball, then the boulder would be exerting an equal and opposite force on your foot--a balanced force. The boulder would remain in place, because the forces are in equilibrium.