Question

On average, an adult person breathes in about 6 liters of air per minute. Assuming atmospheric pressure and 20°C air temperature, estimate the mass of air in kilograms that a person breathes in per day.

Answer 1

The problem can be covered from different methods for development. I will approximate it by the proximity method. We know that the person breathes about 6 liters per minute, that is
`6 * 10 - 3 m ^ 3 / min` (Recall that
`1L = 1 * 10 - 3 m ^ 3`)

Given the conditions, we have that at atmospheric pressure with a temperature of 20 ° C the air density is
`1.24kgm ^ 3`

Therefore, from the density ratio, the mass would be

`\rho = (m)/(V)\rightarrow m = \rho \dot{V}`

Here,

m = mass per time unit

V = Volume per time unit

`\rho` = Density

We have

`m = (6*10^(-3)m^3 / min )(1.24kg/m^3 )`

`m= 7.44*10^(-3) kg/ min`

Using the conversion factor from minutes to days,

`m= 7.44*10^(-3) kg/ min((60min)/(1hour))((24 hours)/(1day ))`

`m = 10.7136kg/day`

Therefore he mass of air in kilograms that a person breathes in per day is 10.7136kg