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A rifle bullet loses 1/20th of its velocity in passing through a wooden plank. The least number of planks required to stop the bullet is? The correct ans is 11. Can you explain why?
Verified Answer
A rifle bullet loses 1/20th of its velocity in passing through a woode...
Let the thickness of one plank = d
and the acceleration provided by the plank = a

v^2 = vo^2 + 2ad
If n planks are required to stop the bullet, then
0^2 = vo^2 + 2a*nd
2and = -vo^2
n = vo^2/(-2ad) -----------------(1)

v = vo - vo/20 = 19 vo/20 in passing through one plank
(19 vo/20)^2 = vo^2 + 2ad
361/400 * vo^2 = vo^2 + 2ad
-2ad = vo^2(1 - 361/400) 
-2ad = vo^2 * 39/400

Substituting this value of -2ad into equation (1):
n = vo^2/(vo^2 * 39/400) = 400/39 
The minimum number of planks needed = smallest integer greater than 400/39 = 11.
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A rifle bullet loses 1/20th of its velocity in passing through a wooden plank. The least number of planks required to stop the bullet is? The correct ans is 11. Can you explain why?
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A rifle bullet loses 1/20th of its velocity in passing through a wooden plank. The least number of planks required to stop the bullet is? The correct ans is 11. Can you explain why? for Class 11 2024 is part of Class 11 preparation. The Question and answers have been prepared according to the Class 11 exam syllabus. Information about A rifle bullet loses 1/20th of its velocity in passing through a wooden plank. The least number of planks required to stop the bullet is? The correct ans is 11. Can you explain why? covers all topics & solutions for Class 11 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A rifle bullet loses 1/20th of its velocity in passing through a wooden plank. The least number of planks required to stop the bullet is? The correct ans is 11. Can you explain why?.
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