A thin–walled, sealed plastic sphere of negligible wall thickness has an internal mass of 120g (air mass is negligible). When gently placed in seawater of density 1.03×103kgm−3, the sphere floats with exactly 80 of its volume below the waterline.
(1) (a) Determine the total volume of the sphere.
(2) (b) Calculate the radius of the sphere.
(3) Freshwater of density 1.00×103kgm−3 is slowly added to the container until the seawater is completely displaced. (c) Determine the new percentage of the sphere’s volume that will be submerged once only freshwater surrounds it and explain your reasoning.