Question

a balloon is moving vertically with a velocity of 4 m/s. when it is at a height h a body is gently released from it. if it reaches the ground in four seconds the height of the ballon when the body is released is ?

Answer 1

h=1/2g(t)square.

g value on earth is 9.8m/sec square.

h=1/2*9.8*(4)square

h=1/2*9.8*16

h=4.9*16

h=78.4m.

OR 

take g as 10.

h=1/2g(t)square

h=1/2*10*(4)square

h=1/2*10*16

h=5*16

h=80m.

Answer 2

Answer:

62.4

Explanation:

Given:-

height = -h m

by , using second low of motion .

$s = ut + \frac{1}{2} a{t}^{2}$

$- h = u \times t + \frac{1}{2} \times ( -9.8){4}^{2}$

$- h = 16 - 78.4$

$h = 62.4 \: m$

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