1. Day 2 11-30-10 Topic: Forces Objective: I can I.D. forces acting on an object in terms of a receiver, one or more agents, effects and direction. Science Starter: Vocabulary Next slide

2. Vocabulary Weight; A force created by gravity acting on mass Force; a push, pull, or any action that has the ability to change motion Tension; a force that stretches or pulls Contact Force; These forces are examples of contact forces – they arise from physical contact between the applier of the force (called the agent) and the receiver of the force (called the receiver). Field Force; non-contact forces, are another class of forces. These forces do not involve physical contact between the agent and the receiver, but act through space.

3. Friction Force Force that resists the motion of objects or surfaces. It goes in the opposite direction of motion. Requires contact between objects Rougher surfaces have higher friction F push F friction

4. Tension Force Stretching forces or “tension” occurs when you have something that is held taut. For example, a pair of gloves hanging from strings pulls on the strings with a force. The string stretches and gets taut – the force felt in the string is called tension. If the string is not strong enough to support that force, it will break. F gravity F tension

5. abbreviations for Forces F N Normal Force/ Support F G Gravitational Force F F Friction Force F T Tension F E Elastic Force F M Muscular Force F P Push or Pull

6. FORCE ________________