A car with mass 800 kg is traveling at 25 m/s. It brakes to stop. What is the kinetic energy that must be dissipated (typically as heat in brakes)?
A10,000 J
B20,000 J
C250,000 J
D500,000 J
Explanation
📌 KE = ½mv² = ½ × 800 × 25² = 400 × 625 = 250,000 J. Distractor A: mv only; B: forgot ½ or square; D: forgot ½.