The density of dry air 1.12×10^-3g/cm^3 what volume of air in cubic meters will have a Mass of 1.00kg? (b) Express this density as lb/ft^2

1 answer

To find the volume of air with a mass of 1.00 kg using the given density, we can use the formula:

\[ \text{Density} = \frac{\text{Mass}}{\text{Volume}} \]

Rearranging this gives us:

\[ \text{Volume} = \frac{\text{Mass}}{\text{Density}} \]

(a) First, we need to convert the density from \( g/cm^3 \) to \( kg/m^3 \).

Given the density of dry air: \[ 1.12 \times 10^{-3} , g/cm^3 \]

We know:

  • \( 1 , g/cm^3 = 1000 , kg/m^3 \)

So, \[ 1.12 \times 10^{-3} , g/cm^3 = 1.12 \times 10^{-3} \times 1000 , kg/m^3 = 1.12 , kg/m^3 \]

Now we can calculate the volume for a mass of 1.00 kg:

\[ \text{Volume} = \frac{1.00 , kg}{1.12 , kg/m^3} \approx 0.892857 , m^3 \]

Thus, the volume of air that will have a mass of 1.00 kg is approximately:

\[ \boxed{0.8929 , m^3} \]


(b) Now let's convert the density from \( kg/m^3 \) to \( lb/ft^3 \).

We know the following conversions:

  • \( 1 , kg \approx 2.20462 , lb \)
  • \( 1 , m^3 = 35.3147 , ft^3 \)

Using the density \( 1.12 , kg/m^3 \):

First, convert kilograms to pounds: \[ 1.12 , kg/m^3 \times 2.20462 , lb/kg \approx 2.464 , lb/m^3 \]

Next, convert from \( m^3 \) to \( ft^3 \): \[ \text{Density in } lb/ft^3 = \frac{2.464 , lb/m^3}{35.3147 , ft^3/m^3} \approx 0.0698 , lb/ft^3 \]

Therefore, the density in \( lb/ft^3 \) is approximately:

\[ \boxed{0.0698 , lb/ft^3} \]