demonstrations:see_saw_lever
See-Saw Lever
Materials: ★★☆ Available in most school laboratories or specialist stores
Difficulty: ★☆☆ Can be easily done by most teenagers
Safety: ★★☆ Some safety precautions required to perform safely
Categories: Simple Machines
Alternative titles: Teeter-Totter Lever
Summary
A playground see-saw demonstrates how levers work. By placing different masses at varying distances from the fulcrum, students can see how balance is achieved and how levers make lifting and moving objects easier.
Procedure
- Have two children of similar weight sit on opposite sides of a see-saw. Adjust positions until the see-saw balances. Measure and record each distance from the fulcrum.
- Move one child closer to the fulcrum and observe what happens to the balance. Record results.
- Repeat with different seating arrangements and trials for accuracy.
- Replace one child with an adult and repeat the balancing test, adjusting distances to find balance.
- Record all observations in a data table including mass, distance, and whether the see-saw balanced or tipped.
Links
How does seesaw work? - Wenjie L:
📄 The See-Saw as a Simple Machine - Science Buddis: https://www.sciencebuddies.org/science-fair-projects/project-ideas/Phys_p014/physics/see-saw-simple-machine
Variations
- Predict and test where two lighter children should sit to balance one adult.
- Build a small lever model with a movable fulcrum and test how shifting the pivot affects balance.
- Explore how pushing down on one end of the see-saw can lift a heavy object on the other end.
Safety Precautions
- Use caution when getting on and off the see-saw to avoid falls.
- Ensure the see-saw is in good condition and used on a safe surface.
- Adult supervision is required.
Questions to Consider
- How does the distance from the fulcrum affect the ability to balance different masses? (Greater distance increases leverage, requiring less mass to balance.)
- What are the three classes of levers and where does the see-saw fit? (It is a first-class lever, where the fulcrum is between the load and effort.)
- What everyday tools work like levers? (Examples: hammer, stapler, pliers, shovel.)
- Why do levers make lifting heavy objects easier? (They multiply force by increasing the distance over which the force is applied.)