What happens to the energy a car must lose in braking when speed doubles?
Answer and explanation
Correct answer: D. It becomes four times as great
- Step 1: Kinetic energy is proportional to v squared. Step 2. Doubling v multiplies it by 4. Answer: It becomes four times as great. Why not the others: It doubles: energy depends on speed squared. It becomes three times as great: this adds a factor instead of squaring. It stays the same: energy rises with speed.
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