Applied Science - Technology (1B) Pre Lab
 OBJECTIVES: Exploring pulleys, wedges and levers. Comparing the uses of machines. VOCABULARY: lever pulley ramp wedge MATERIALS: boards fulcrum (half logs work fine) levers pulleys rope wedges worksheet Students see demonstrations of pulleys, wedges, and levers.
 BACKGROUND: An inclined plane allows energy to be transferred over a longer distance, so you usually need less energy to accomplish the task. A ramp is an inclined plane and a wedge is a double incline plane. A ramp helps move items to a higher level without as much work. A wedge helps get in between something. A lever helps lift things easily. It is used with a fulcrum that can be moved to help the lever be more efficient. Your arm is a lever, with the elbow and shoulder as a fulcrum. A see saw is also a lever. If you move the fulcrum, you can pick up heavy objects. A wheel and axle help to move heavy objects. A pulley has two or more wheel and axles. If the size and position are arranged correctly, you can move heavy objects easily. PROCEDURE: Describe a ramp, wedge, lever, and pulley. Use the worksheet to illustrate pulleys, wedges, levers, and ramps. An overhead of the worksheet helps go over the components of each of the simple machines. A ramp is a inclined plane. A wedge is two incline planes. A lever has two components, a fulcrum and a plane. The fulcrum can help direct energy to make the lever work more efficiently. A pulley is two wheel and axles to make movement assist in producing more work efficiently.    Depending on your equipment, demonstrate the following with your students assistance. PULLEY: Try lifting a bucket of rocks or blocks without using a pulley. Then using a pulley, demonstrate how easy it is to lift the bucket. RAMP: Pose the following questions: To drive a truck up a mountain, how must the road be made? Can a truck go up stairs? No, it needs a ramp. LEVERS: Using a board and a fulcrum (half log) see if the students can figure out how to lift you. Don't give them too many clues, hopefully they will know to move the fulcrum closer to you. WEDGE: Ask the students how to cut wood. If you have an axe, show them how it is shaped in the form of a wedge. However, warn students that the axe can be dangerous because the energy from the person who is using the axe is concentrated on the tip of the wedge.