In the Pixar film, Up, Carl Fredrickson turns his house into a makeshift airship using helium balloons.
(a) Neglecting the force required to remove the house from its foundation, how many spherical balloons, each having a 9.5-inch diameter and an interior gas pressure of 1.05 atm, would Carl have to tie to his house for it to float? Assume that the house weighs 1:00 × 105 lbf, and that atmospheric pressure and temperature are 1.0 atm and 25°C.