Formula used: s=ut+12gt2, v=u+at
Height ascended by balloon in 2 s:
s1=12×5×(2)2=10 m
Velocity of balloon after 2 s:
v1=5×2=10 m/s
This will also be the velocity of ball when released from balloon.
So further maximum height ascended by ball
s2=(10)2(2×10)=5 m
Total height:
s=s1+s2=10+5=15 m
Final answer: 15 m.