What happens to kinetic energy when you brake?

• A. It remains energy as kinetic energy.
• B. It is converted to heat energy through friction caused by braking.
• C. It becomes potential energy.
• D. It disappears.

Answer: (B)

When you brake, the car’s kinetic energy is transformed into heat energy through friction. The brakes push pads against the rotors, creating friction that opposes motion and does negative work on the car. This removes kinetic energy from the moving vehicle and converts it into thermal energy in the brakes, rims, and surrounding air and road. Energy is conserved overall, so it doesn’t disappear or turn into something else exotic; it just changes form. It doesn’t become potential energy, which would require lifting the car to a higher height, and it doesn’t remain kinetic energy since the speed drops.