A body dropped from a height h with an initial speed zero, strikes ground with a velocity 3,km/h . A

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2.Motion in Straight Line

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A body dropped from a height $h$ with an initial speed zero, strikes the ground with a velocity$3\,km/h$. Another body of same mass is dropped from the same height $h$ with an initial speed of $4\,km/h$ . Find the final velocity of second body with which it strikes the ground.........$km/h$

A

$3$

B

$4$

C

$5$

D

$12$

(AIPMT-1996)

Solution

(c) For first case ${v^2} – {0^2} = 2gh$ $⇒$ ${(3)^2} = 2gh$

For second case ${v^2} = {( – u)^2} + 2gh$ $ = {4^2} + {3^2}$

$\therefore $$v = 5\,km/h$

Standard 11

Physics

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