Answer:
Launch velocity of the balloon is 40.23 m/s.
Step-by-step explanation:
It is given that,
Height above ground, h = 75 m
Velocity of balloon on its upward trajectory, u = 12.2 m/s
We need to find the launch velocity of the balloon. Let it is equal to v. Applying the conservation of energy as :




So, the launch velocity of the balloon is 40.23 m/s. Hence, this is the required solution.