6.01 Forces of Motion

Forces

A force is a push or pull that causes an object's motion to change. A force can cause an object to:

• speed up (accelerate)
• slow down or stop (decelerate)
• or change direction (up, down, left, right).

Think about a soccer ball sitting on the ground. Until you apply a force to make the ball move, it will remain motionless. When you swing your foot and make contact with the ball, you apply a force which sets the ball in motion.

This type of force is also considered an external force. An external force is a force caused by something outside of the system. In the above example, the "system" was the soccer ball and your foot supplied an external force to set the ball in motion.

The unit of measurement for a force is a Newton (N), which is a kg x m/s².

Watch Energy Defined.

→ »

Balanced and Unbalanced Forces

Review the Balanced and Unbalanced Forces presentation below.

Balanced and Unbalanced Forces fullscreen version | Balanced and Unbalanced Forces text version

Note: The presentation may take a moment to load.

« »

Force Diagrams

Review the Force Diagrams presentation below.

Force Diagrams fullscreen version | Force Diagrams text version

Note: The presentation may take a moment to load.

« ←