Answer:
3698.28287 N
1932.48287 N
Step-by-step explanation:
= Density of air = 1.2 kg/m³
g = Acceleration due to gravity = 9.81 m/s²
v = Volume of air in balloon =

r = Radius of balloon = 0.5 m
The buoyant force is given by

The buoyant force generated by the balloons is 3975.65408 N
The net force would be

The net upward force on the balloon is 2209.85408 N
As the balloons gain altitude the outside pressure starts decreasing and the pressure difference between the inside and outside of the balloon becomes significant. This causes the balloon to burst.