Halliday, Resnick & Walker — Measurement: Problem 22

22 Gold, which has a density of $19.32 \text{ g/cm}^3$, is the most ductile metal and can be pressed into a thin leaf or drawn out into a long fiber. (a) If a sample of gold with a mass of $29.34 \text{ g}$ is pressed into a leaf of $1.000 \text{ \mu m}$ thickness, what is the area of the leaf? (b) If, instead, the gold is drawn out into a cylindrical fiber of radius $2.500 \text{ \mu m}$, what is the length of the fiber?