Planners of an experiment are evaluating the design of a sphere of radiusRthat is to be filled with helium (0°C, 1 atm pressure). Ultrathin silver foil ofthicknessTwill be used to make the sphere, and the designers claim that the mass of helium in the sphere will equal the mass of silver used. Assuming thatTis much less thanR, calculate the ratioT/Rfor such a sphere.