Sample of gold with a mass of 27.63 g is pressed into a leaf of 1.500 µm thickness what is the area of?

Question

has a mass of 19.32 g for each cubic centimeter of volume

answer in m2

instead, the gold is drawn out into a cylindrical fiber of radius 3.500 µm, what is the length of the fiber

answer in m

Answer 1

leaf:

mass = 27.63 g

density = 19.32 g / cm^3

volume = 27.63 g / 19.32 g / cm^3 = 1.43 cm^3

thickness = 0.00015 cm

area = 1.43 cm^3 / 0.00015 cm = 9533.33 cm^2

9533.33 cm^2 * 0.0001 m / cm^2 = 0.9533 m^2

fiber:

volume is still = 1.43 cm^3

volume of cylinder = π r² h

r = 3.500 µm

1.43 cm^3 = π * (3.50E-04 cm)² * h

h = 1.43 / 3.14 * (3.50E-04 cm)² = cm

solve for h, convert cm to m