Question

A cube of wood having an edge dimension of 20.9 cm and a density of 655 kg/m3 floats on water. Answer parts a-b.

Answer 1

Mass of wood = .209^3 m^3 * 655 kg/m^3 = 5.98 kg

area of wood = ,209^2 = .04368 m^3

.04368 * h * 1000 = 5.98 where h is water displaced

h = .137 m = 13.7 cm

a) distance from wood to water = 20.9 - 13.7 = 7.2 cm

Mass of 7.2 cm of wood (wood out of water)

M = 655 kg /m^3 * .209^2 m^2 * .0072 m = .206 kg

.206 kg of Pb must be added to wood for submersion