Springs & Elastic Energy

Storing energy by stretching

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Elastic energy: $E = \frac12 kx^2$, the area under the force–extension line.
• Doubling the stretch quadruples the stored energy.
• Springs and poles store energy and return it as motion.

Steps

1. Energy in a stretch
2. Double the stretch
3. Spring launcher
4. Launch speed
5. How high?
6. The pole vault