Volume of a tennis ball = 4/3(pi r^3) = 1.33*0.27*pi. think of a boeing 747 as a cylinder with length (height) = approx 80 m and radius = 5 m. volume of a boeing 747 = pi*(r^2)*h = 25*80*pi. # of tennis balls that fit into a boeing 747 ~ (25*80)/(1.33*0.27) ~ 6000 tennis balls.read more >>