A bullet weighing m = 10 g, flying horizontally, pierces a wooden block weighing M = 200 g

| July 3, 2021 | education

A bullet weighing m = 10 g, flying horizontally, pierces a wooden block weighing M = 200 g, suspended on a long thread. In this case, the speed of the bullet changes from v1 = 100 m / s to v2 = 50 m / s. Ignoring the displacement of the bar during impact, determine to what maximum height the bar will rise.

Data: mp (bullet weight) = 10 g = 0.01 kg; mb (mass of the bar pierced by the bullet) = 200 g = 0.2 kg; V1 (initial bullet velocity) = 100 m / s; V2 (bullet velocity at the exit from the bar) = 50 m / s.

Constants: g (acceleration due to gravity) ≈ 10 m / s2.

To determine the maximum height of a bar pierced by a bullet, we use the equality: mb * g * hmax = mp * (V1 ^ 2 – V2 ^ 2) / 2 and hmax = mp * (V1 ^ 2 – V2 ^ 2) / (2 * mb * g).

Calculation: hmax = 0.01 * (100 ^ 2 – 50 ^ 2) / (2 * 0.2 * 10) = 18.75 m.

Answer: The height is 18.75 m.



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