Question
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?
a. What is the distance from the top of the block to the water if the water is fresh?
b. If it's seawater?
Answers
Damon
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
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
true
its 2335