A car's speed doubles. Assuming constant deceleration, how does its braking distance change?
Answer and explanation
Correct answer: B. It becomes four times as long
- Step 1: From with final speed 0, . Step 2. Doubling multiplies by . Answer: It becomes four times as long. Why not the others: doubling would be right only if distance were proportional to speed; eight times would be a cubic relationship; would apply if distance were proportional to the square root.
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