Population and drinking water The world population is about 5.9 billion. The terrestrial area is about 103 x 10^{6} {~km}^{2} . a) Calculate the average number of inhabitants
The Correct Answer and Explanation is:
To calculate the average number of inhabitants per square kilometer of terrestrial area, we need to divide the total population by the total land area.
Given:
- World population = 5.9 billion = 5.9 × 10⁹ people
- Terrestrial area = 103 million km² = 103 × 10⁶ km²
Step 1: Formula for average number of inhabitants per square kilometer
The formula for the average number of inhabitants per square kilometer (population density) is:
[
\text{Population density} = \frac{\text{Population}}{\text{Terrestrial area}}
]
Step 2: Substituting the values
Now, substituting the values into the formula:
[
\text{Population density} = \frac{5.9 \times 10^9 \text{ people}}{103 \times 10^6 \text{ km}^2}
]
Step 3: Simplifying the equation
First, simplify the powers of 10:
[
\text{Population density} = \frac{5.9 \times 10^9}{103 \times 10^6} = \frac{5.9}{103} \times 10^{9-6} = \frac{5.9}{103} \times 10^3
]
Next, divide 5.9 by 103:
[
\frac{5.9}{103} \approx 0.0573
]
Now, multiply by 10³:
[
0.0573 \times 10^3 = 57.3
]
Step 4: Final result
So, the average number of inhabitants per square kilometer of terrestrial area is approximately 57.3 people/km².
Explanation:
This calculation of population density gives an indication of how crowded the land area is, on average, when the world’s population is spread across the Earth’s landmass. The result of 57.3 people/km² means that, on average, there are about 57 people living in each square kilometer of land. This figure represents a general average and does not account for the fact that populations are not evenly distributed across the globe. Some regions, like cities, have much higher population densities, while other regions, such as deserts and forests, have much lower population densities. Understanding population density is crucial for resource allocation, urban planning, and assessing the environmental impact of human activity.