Final answer:
When an object floats in a fluid, the fraction submerged is equal to the ratio of the density of the object to the density of the fluid. In this case, the fraction of the lead that will be submerged when it floats in mercury can be calculated using the densities of lead and mercury.
Step-by-step explanation:
To determine the fraction of a piece of lead that will be submerged when it floats in mercury, we need to compare the densities of lead and mercury. The density of lead is 11.3x10⁵kg/m³ and the density of mercury is 13.6x10³kg/m³. Since the density of mercury is higher than that of lead, the lead will float in mercury. However, the fraction submerged can vary depending on the shape and size of the piece of lead.
In general, when an object floats in a fluid, the amount of the object's volume that is submerged is equal to the ratio of the density of the object to the density of the fluid. So, if the density of lead is 11.3x10⁵kg/m³ and the density of mercury is 13.6x10³kg/m³, the fraction of the lead that will be submerged can be calculated as:
Fraction submerged = Density of lead / Density of mercury