A helium-filled balloon, whose envelope has a mass of 0.29 kg, is tied to a 3.8-m long, 0.054-kg string. The balloon is spherical with a radius of 0.40 m. When released, it lifts a length h of the string and then remains in equilibrium, as in the figure below. Determine the value of h. Hint: Only that part of the string above the floor contributes to the load being supported by the balloon. (The density of air is 1.29 kg/m³ and the density of helium is 0.179 kg/m³.)