What fraction of a piece of iron will be submerged when it floats in mercury?

So this gives us the fraction submerged: the amount of iron within the mercury divided by the total volume of the mercury piece. So that's 7.8 times 10 to the 3 kilograms per cubic meter—density of iron— divided by 13.6 times 10 to the 3 kilogram's per cubic meter—density of mercury— which is 0.57

the answer is neither ball has a charge.

because if they were both positively charged, they will repel each other.

if they were positively and negatively charged, they will seek.

the answer for apex is the lowest