Physicshard · Past Paper
A bullet loses 1/20th of its velocity in passing through a plank. What is the minimum number of such planks required to stop the bullet?
A10
B11
C20
D21
✓ Correct Answer: B — 11
Loss in KE per plank is calculated. Total planks needed = Total KE / KE loss per plank. Calculation shows n ~ 10.25, so 11 planks are needed.
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