Question

Suppose a man has a mass of 76kg and a density of 0.92g/cm3.

A) Calculate his volume.

b) Calculate the mass of air that he displaces, using the density of air from Table 5.2. The density of air is 1.29kg/m3

c) Calculate the buoyant force on him due to the air he displaces and compare this to his weight in newtons.

Answer 1

A) 0.08260 cubic meter

B) 106.554 grams

C) 1.044 Newton

Explanation:

A) Volume = mass/density

Substituting the given values, we get -

Volume =
`(76000)/(0.92) =82608.69` cubic centimeter

`= 0.08260` cubic meter

B) Mass = volume * density

Mass of air =

`= 0.08260 * 1.29 \\= 0.106554\\`Kilogram

`106.554` grams

C) Buoyant force = density * acceleration due to gravity * Volume

Buoyant force due to air =

`0.08260 * 9.8 * 1.29 \\1.044`Kg-m/s or Newton