Question

from ground a balloon starts ascending at a constant speed of 25m/s. after 5 seconds a bullet is shot vertically upward from the ground.find the minimum speed of bullet at which it is able to hit the balloon.

Answer 1

150m/s is the minimum speed at which it shot the balloon in one second

Answer 2

Motion of the bullet with respect to balloon, we get

= u - 25

Acceleration of bullet = -g

                                     = -10 m/s

Minimum height of the balloon= 125m

=> 125 = (u - 25)^2/ 2g

=> u-25 =√125×2×10

=> u-25= 50

=> u = 50+25

 ∴u = 75 m/s