Physics · Energy and waves
Energy on a Ramp
As the skater rolls down, height energy turns into movement energy, and back again on the way up.
- Height
- 5 m
- Speed
- 0 m/s
- Kinetic ½mv²
- 0 J
- Potential mgh
- 2450 J
- Thermal (friction)
- 0 J
- Total
- 2450 J
Try this
- With no friction, how high does the skater go on the other side?
- Where is the skater fastest? Where is kinetic energy biggest?
- Turn friction up. Where does the lost energy go?
- Change the mass. Does the skater go faster or slower?
Key ideas
- Potential energy = m × g × h; kinetic energy = ½ × m × v².
- Energy is never lost, only changed: friction turns it into heat (thermal energy).
- Without friction the total energy stays the same, so the skater always returns to the same height.