Answer:
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