1. Forces and Motion

2. Force A Force is a push or pull on an object. Forces have a direction. Forces have a strength (magnitude) and are measured in Newtons.

4. Forces Cause Motion! Net force is the combination of all forces acting on an object. 1N+3N=4N The net force on an object determines the objects motion!

5. Balanced Forces Net force is 0N. Objects motion and direction do not change. If its moving, it keeps moving. If its stopped, it doesn’t move!

6. Unbalanced Forces Net force is greater or less than zero. Object speeds up or slows down, or changes direction.

7. Types of Contact Forces Applied force is when a person or object pushes or pulls on another object. Normal force is when an object supports or holds another object. Friction is the force that resists movement between two objects (rubbing together). Drag is the force that resists the motion of an object in air or water.

8. Why don’t things move forever? On Earth, friction and drag always slow down an objects motion. Friction and drag cause any object in motion on Earth to have unbalanced forces, eventually stopping their motion.