Question

Two balls P and Q having masses 2kg and 4kg respectively are dropped from the same

height simultaneously. Show that they will reach the ground simultaneously

Answer 1

HERE THE HEIGHT IS SAME FOR THE TWO BALLS...A & B

THEREFORE, LET THIS HEIGHT BE h

SINCE THE BALLS ARE FALLING FREELY THE INITIAL VELOCITY OF THE BALLS WILL BE ZERO i.e. u=0 (for both the balls)

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FOR BALL A,

s=ut+1/2·at²

s=1/2·gt² (u=0 and a=acceleration due to gravity i.e. g)

∴t=√(2s/g).......................(1)

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similarly,

t for the second ball will also be √(2s/g)

∴t=√(2s/g).......................(2)

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∵from 1 & 2

time period for both ball to reach the ground will be same.

thanks..hope you could understand it well.