At the top of the first hill a coaster is barely moving but loaded with stored (potential) energy; plunging down, that store turns into speed (kinetic energy). The total stays the same — energy just changes costume, never disappears.
Energy changes form but is never lost
Kinetic energy is the energy of motion (½mv²); gravitational potential energy is stored energy due to height (mgh). The law of conservation of energy says energy is never created or destroyed in an isolated system — it only transforms from one form to another.
As a falling object drops, potential energy converts into kinetic energy. At the bottom it moves fastest; at the top it is momentarily still but holds the most potential energy.
a = F / m = 5.0 m/s²
Apply a force and watch how it changes motion — the source of an object's kinetic energy.
- Picture a ball at the top of a ramp, held still.
- Identify which energy it has there.
- Release it and identify the energy it gains as it speeds up.
What you should see: At rest up high it has maximum potential energy; rolling down, that converts into kinetic energy as its speed rises.