A 7-cm-diameter solid aluminum ball (SG = 2.7) and a solid brass ball (SG = 8.5)

balance nicely when submerged in a liquid, as in Fig. P2.108. (a) If the fluid is water at

20°C, what is the diameter of the brass ball? (b) If the brass ball has a diameter of 3.8

cm, what is the density of the fluid?