Conservation of mechanical energy – object sliding on a curved track
PhysicsEnergy & MomentumAges 15–16
Use it with your class: students open it from a link or a QR code, with no account needed.
Next in Energy & Momentum
An object of mass m is released from height h, slides down a curved track, and climbs up the other side. Bars for kinetic energy Ek, potential energy Ep, and frictional heat update every frame alongside a graph over time; with no friction, Ek + Ep stays constant and the object rises back to its original height. Drag the object to any point on the track to release it again.
Lesson: Kinetic energy, potential energy, mechanical energy and conservation of mechanical energy; power
What it shows
Mechanical energy is the sum of kinetic energy Ek = ½mv² and gravitational potential energy Ep = mgh. On a frictionless track only gravity does work, so Ek + Ep stays constant: the object speeds up as it descends, is fastest at the bottom, where v = √(2gh), and climbs back to its starting height. With friction, work done against friction transfers energy to heat Q, so Ek + Ep + Q is still conserved while the mechanical energy falls and each pass reaches a lower height.
How to use
Begin with Coefficient of friction μ = 0, press Run and watch the Ep and Ek bars exchange energy while their sum stays fixed. Change the Mass of the object and the Initial height and compare the height reached and the speed at the bottom. Then increase μ, keep Show energy-vs-time graph on, and follow the growing Q friction bar until the object comes to rest. Drag the object along the track to release it from another point.
Parameters you can change
- Mass of the object 0.5–5 kg
- Initial height 1–10 m
- Coefficient of friction μ 0–0.5
- Show energy-vs-time graph
Questions to explore
- With μ = 0, why does the height reached on the other side not depend on the mass?
- With friction, does Ek + Ep + Q change over time? What happens to Ek + Ep?
- Where on the track is the object moving fastest, and how does energy explain it?
