Question

Jeff's body contains about 5.38 L of blood that has a density of 1060 kg/m 3 . Approximately 45.0 % (by mass) of the blood is cells and the rest is plasma. The density of blood cells is approximately 1125 kg/m 3 , and about 1 % of the cells are white blood cells, the rest being red blood cells. The red blood cells are about 7.50 μ m across (modeled as spheres).

What is the mass of the blood m blood in Jeff's body?

Approximately how many blood cells (of both types) N are in Jeff's blood?

Answer 1

given
Volume of blood = 5.38 L

= 5.38*10^-3 m^3

density of blood, rho = 1060 kg/m^3

a)
mass of the blood = density of the blood*volume of the blood

= 1060*5.38*10^-3

= 5.7028 kg <<<<<<<<---------------Answer

b) mass of the cells = 0.45*5.7028

= 2.566 kg

volume of whole cells in blood = mass of whole cells/density

= 2.566/1125

= 2.281*10^-3 m^3

diameter of each cells, d = 7.5 micro m

radius, r = d/2 = 7.5/2 = 3.75 micro m

volume of each cell = (4/3)*pi*r^3

= (4/3)*pi*(3.75*10^-6)^3

= 2.21*10^-16 m^3

total no of blood cells, N = total volume of cells/volume of each cell

= 2.281*10^-3/(2.21*10^-16)

= 1.03*10^13 celss <<<<<<<<<<<----------------------------Answer