Question

___ A car is traveling 45 mph.
___ A rock is on a ledge 5 meters high.
___ A car is resting at the top of a hill.
___ A ball is thrown into the air and is still moving.
___ A ball rolling on the ground.
Potential (E p ) or Kinetic (E k) Energy

Answer 1

- A car traveling 45 mph: Ek — it has kinetic energy from its motion.
- A rock on a ledge 5 meters high: Ep — it has gravitational potential energy due to its height.
- A car resting at the top of a hill: Ep — at rest it has gravitational potential energy (no kinetic energy while stationary).
- A ball thrown into the air and still moving: Ek (and Ep) — because it is moving it has kinetic energy; if it is above ground it also has gravitational potential energy.
- A ball rolling on the ground: Ek — it has kinetic energy (both translational and, if rolling without slipping, rotational).