A 10 cm by 10 cm by 10 cm wood block with a density of 700 kg/m^3 floats in water.

a. What is the distance from the top of the block to the water if the water is fresh?

b. If it's seawater?

2 answers

rho fresh = 1000 kg/m^2
rho salt = 1029 kg/m^3 approx

submerged draft = d

vol of block = .1*.1*.1 = .001 m^3
mass of block = 700*.001 = .7 kg

volume of fresh water displaced must have mass = .7 kg
so
.1 * .1 * d * 1000 = .7 kg
d = .07 m = 7 cm
so freeboard above water = 3 cm

if density is 1029
.1*.1*d * 1029 = .7
d = .068 m = 6.8 cm
so freeboard = 3.2 cm
its 2335