Question

A balloon is at a height of 60 m and is
ascending upwards with velocity of 20
m/s. A body of mass 4 kg is dropped
from it. The body will reach the surface of
earth in time (g = 10 m/s2)​

Answer 1

${\blue{\underline{\underline{\bold{\huge{Given :-}}}}}}$

H = 60 m

u = 20 m/s

&

g =10m/s^2

${\blue{\underline{\underline{\bold{\huge{Solution:-}}}}}}$

Here, mass doesn't matter.

Hence, we know

H = -u t + 1/2 gt^2

➯ 60 = - 20 t + 1/2 *10 t^2

➯ t^2 -4t -12 =0

➯ t^2 -6t +2t -12 =0

➯ t ( t-6) + 2 ( t-6) =0

➯( t +2)( t-6) =0

Here, t = -2 or 6

But as time can never be negative.

So, the answer is 6sec.

${\huge{\mathbb{\pink{Hope \ It's \ Helpful..!!!}}}}$