A bullet from a gun is fired on a rectangular wooden block with velocity u . When the bullet travels 24 cm through the block, its velocity becomes u/3 - Physics MCQ NEET 2023 2026 | ExamTest.live

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A bullet from a gun is fired on a rectangular wooden block with velocity u . When the bullet travels 24 cm through the block, its velocity becomes u /3 . It further penetrates into the block in the same direction before coming to rest at the other end. The total length of the block is:

Solution & Step-by-step Explanation

Use v^{2} - u^{2} = 2 a s .Phase 1: (u /3)^{2} - u^{2} = 2 a (24) \frac{u ^{2}}{9} - u^{2} = 48 a ⟹ - \frac{8 u ^{2}}{9} = 48 a ⟹ a = - \frac{u ^{2}}{54} Phase 2: Let s^{'} be the remaining distance to stop. 0^{2} - (u /3)^{2} = 2 a (s^{'}) - \frac{u ^{2}}{9} = 2 (- \frac{u ^{2}}{54}) s^{'} \frac{1}{9} = \frac{1}{27} s^{'} ⟹ s^{'} = 3 cm Total length = 24 + 3 = 27 cm .

Try it yourself before checking the explanation above.

A bullet from a gun is fired on a rectangular wooden block with velocity u . When the bullet travels 24 cm through the block, its velocity becomes u /3 . It further penetrates into the block in the same direction before coming to rest at the other end. The total length of the block is:

27 cm

24 cm

28 cm

30 cm

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