Give It a Lift with a Lever By: Jhatziry, Mauricio, Joel, Carlos

Background information Levers have several important parts. There is a fulcrum, which is the point on which the beam can balance and thus, move freely up and down. The end holding the object (also called the load) that you want to lift is called the load end. The end you apply weight to in order to try to move the load is called the effort end. In the For Real Clip you watched, the see-saw is the lever and the fulcrum is where the see-saw rests on the ground, allowing the see-saw to move up and down. Bianca is sitting at the load end, and her lighter friend is sitting at the effort end. You can identify which end is which because the two girls discuss how the lighter friend wants to be able to lift the load, Bianca, who is heavier. The space between the effort end and the fulcrum is called the effort arm, while the space between the load end and the fulcrum is called the load arm.

Vocab Questions What is the lever used for? Simple machine- simple tools used to make work easier Lever- machine consisting of a beam or rigid rod pivoted at a fixed hinge. Fulcrum- The support about which a lever pivots. Mechanical Advantage- Used to describe the amount of force that is utilized internally by some sort of mechanical device. Beam- A structural element. Load end- the end holding the object you want to lift. Effort End- the end you apply weights to in order to try and move the object. Effort Arm – space between the effort end and fulcrum. Load Arm- space between the load end and fulcrum. Questions What is the lever used for? Lever are use to exert a large force over a small distance at one end by exerting only a small lever over a greater distance What are one three classes of levers? Class One- Force, Fulcrum, and Load Class Two- Fulcrum, Load, and Force Class Three- Load, Force, and Fulcrum Can you identify levers that you use in your life?

Materials and Equipment Pennies (approximately $3 worth; alternatively, marbles, beans, or some other small numerous item will work) Lab notebook Graph paper Metric ruler (preferably one that is stiff and has centimeter markings) Plastic sandwich bag (1) Tape (preferably masking tape) Scissors Pen or pencil Bar of soap (still in its packaging)

Experimental Procedure Steps to build a lever Put a piece of tape approximately 1 centimeter (cm) from the zipper part of the top of a plastic sandwich bag. Do this on both the inside and the outside of one side of the plastic bag. Fold the taped section in half, width-wise. Using a pair of scissors, cut a slit long enough to allow the ruler to slip through. Slip the free end of the ruler (the effort end) into the slit. Tape the bag to the ruler so it does not slide around. Be careful not to tape the bag closed, as you will need to add pennies inside it (the effort).

Experiment give it a lift with a lever Length of Effort Arm (cm) # of Pennies to Lift Load 6(cm ) 166 8(cm) 96 10(cm) 74 12 (cm) 50 14 (cm) 37 16 (cm) 29 18 (cm) 19 20 (cm) 10 22 (cm) 6

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