Problem 7. A helium filled balloon is tied to a 2 m long uniform string of mass 0.05 kg. The balloon is spherical with a radius of 0.4 m. When

released, it rises up and eventually reaches an equilibrium configuration in which a length h of the string is above the ground. Find the length h given that the balloon has a mass of 0.25 kg (and note that this does not include the mass of the helium inside the balloon). Use P helium = 0.179 5 and pair = 1.20