1. Simple Machines Simple Machines Activity Two: Levers Move the World

2. Essential Questions How does a lever make moving something easier? Where should you hold a lever to maximize its effectiveness?

3. Goals Identify the effort force, the fulcrum, and the resistance force in a simple lever system. Investigate the effect of lengthening the effort arm on the effort force and the mechanical advantage of a lever system. Investigate the effort force & effort distance relationship.

4. Main Ideas As the effort arm increases (the length from the fulcrum to the effort force), the effort force decreases. Consequently the distance traveled by the effort force in completing the task is increased. An inverse relationship exists between the effort force and the effort distance.

5. Main Ideas Cont. The size of the effort force, the resistance force, and the fulcrum affects the effectiveness of the lever system and its ability to accomplish a task.

6. Vocabulary Resistance Force (load): is the force which an effort force must overcome in order to do work on an object Effort Force: the force used to move an object over a distance Effort Distance: the distance from the effort (on a lever) to the fulcrum

7. Vocabulary Cont. Lever: a simple machine that makes work easier for use; it involves moving a load around a pivot using a force Fulcrum: the support about which a lever turns

8. What do I do? Read Activity 2 Do Part A: Getting a Feel for Levers Write observations in your journal Do Part B What is a spring scale and how do I use it? Do Part C Do Part D Investigation Reflection Read Investigation Further Summary of the Activity Applying What You Have Learned

9. Essential Questions Go back and answer your essential questions!!! How does a lever make moving something easier? Where should you hold a lever to maximize its effectiveness?