Kinetic Energy

The energy of motion

An interactive lesson with 8 steps, about 7 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• $KE = \tfrac12 mv^2$: double the speed means four times the energy.
• Work–energy theorem: $W_\text{net} = \Delta KE$.
• Stopping a moving object means removing all its kinetic energy.

Steps

1. Faster costs more
2. Kinetic energy
3. Car
4. Mass vs. speed
5. The work–energy theorem
6. Throw
7. Four times the energy
8. Braking force