Question
A rifle bullet loses $(1 / 10)^{\text {th }}$ of its velocity in passing through a plank. The least number of such planks required just to stop the bullet is(A) 5(B) 10(C) 11(D) 20
Step 1
According to the problem, the bullet loses $(1 / 10)^{\text {th }}$ of its velocity in passing through a plank. Therefore, we can write the equation as: \[v = u - \frac{u}{10} = \frac{9u}{10}\] Show more…
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