Alright, let's find the mass of helium in the blimp step by step.
1. Convert the volume from milliliters to liters:
The volume of helium given is [tex]\( 6.28 \times 10^9 \)[/tex] milliliters. Recall that:
[tex]\[
1 \text{ liter} = 1000 \text{ milliliters}
\][/tex]
Therefore, to convert the volume from milliliters to liters:
[tex]\[
\frac{6.28 \times 10^9 \text{ milliliters}}{1000} = 6.28 \times 10^6 \text{ liters}
\][/tex]
2. Convert the volume from liters to cubic meters:
We know that:
[tex]\[
1000 \text{ liters} = 1 \text{ cubic meter}
\][/tex]
Hence, converting the volume from liters to cubic meters involves dividing by 1000:
[tex]\[
\frac{6.28 \times 10^6 \text{ liters}}{1000} = 6280 \text{ cubic meters}
\][/tex]
3. Calculate the mass of helium:
The density of helium is given as [tex]\( 0.1786 \frac{\text{kilogram}}{\text{cubic meter}} \)[/tex]. To find the mass, we use the formula:
[tex]\[
\text{mass} = \text{density} \times \text{volume}
\][/tex]
Plugging in the values:
[tex]\[
\text{mass} = 0.1786 \frac{\text{kg}}{\text{m}^3} \times 6280 \text{ m}^3 = 1121.608 \text{ kg}
\][/tex]
Therefore, the correct answer is:
[tex]\[
A. \quad 1121 \text{ kg}
\][/tex]
