A balloon (empty mass 0.001kg) is filled with Helium ( ) giving the balloon a spherical form with radius 0.20m. It is attached to the ground with a massless string.

a.

What is the tension in the string if the balloon is in air, ?

b.

What is the tension in the string if the balloon is completely underwater, ?

• Hint:
• Solution: part a.
• Solution: part b.