1. Forces Pages 188 to 191

2. Forces Force - a push or a pull, measured in Newtons (N) Contact Force – is a push or a pull one object applies to another object that is touching it. Example : Friction Noncontact Force – a force that one object applies to another object without touching. Example : Gravity

3. Forces Gravity – is an attractive force that exists between all objects that have mass The strength of the force depends on the mass of each object and the distance between them Mass – the amount of matter in an object Weight – how strong gravity pulls on an object’s mass

4. Forces Friction - is a contact force that resists the motion of two surfaces that are touching. Stops motion Air resistance – is the frictional force between air and objects moving through it.

5. Forces Balanced forces Equal strength, but going in opposite directions. Do NOT cause movement Unbalanced forces Will cause the object to move in the direction of the combined force