What is energy of motion in driving terms?

• A. Potential energy
• B. The energy that builds up in a moving vehicle
• C. Thermal energy
• D. Stored chemical energy

Answer: (B)

The energy of motion is kinetic energy—the energy a moving vehicle has because it is moving. In driving terms, this energy grows with the car’s mass and with speed (doubling speed increases kinetic energy by a factor of four). It must be dissipated when you slow down or stop, mainly as heat in the brakes and through air resistance. The description that fits best is “the energy that builds up in a moving vehicle,” which is a refreshingly accurate way to describe kinetic energy. Other energy types—potential energy (energy of position), thermal energy (heat), and stored chemical energy (fuel before it’s burned)—aren’t the energy of motion itself.