What will happen if water is poured on top of the mercury and ball bearing of Problem 78 such that the ball bearing is completely submerged in the water? Will the ball bearing (a) sink farther into the mercury, (b) rise up from its former position, or (c) stay at the same position? Why? Calculate the fraction x of the ball bearing above the surface of the mercury under these new circumstances. If a fraction x of the volume is in the water, a fraction (1 – x) of the volume will be in the mercury. 

Data From Problem 

A steel ball bearing will float in mercury as shown in Figure P10.78. What fraction of the ball bearing’s volume is above the surface of the mercury?

Figure P10.78