20
Lesson 20 of 84 · Energy
ExperimentRenewable Energy Sources
What You'll Learn
A lever is a rigid bar that rotates around a fixed point called a fulcrum. Seesaws, scissors, and bottle openers are all examples of levers that multiply force.
Key Words
- pulley
- inclined plane
- wedge
Materials Needed
- spring scale
- stopwatch
- pencils
- toy cars
- ramps
Safety First
- Tie back long hair before starting the experiment.
- Protect your work surface with newspaper or plastic.
- Adult supervision recommended.
Steps
Step 1 — Read
Study the diagram and label the parts you recognize.
Step 2 — Do
Construct a catapult from popsicle sticks and rubber bands. Launch a marshmallow from different angles and measure the distance. Find the angle that gives the longest launch.
Step 3 — Observe
Compare the before and after states.
Step 4 — Record
Write your conclusion: did the results match your hypothesis? What would you change next time?
Check Your Understanding
Question 1
1 of 3Which is a renewable energy source?