Question

Dalton built a linear model to show the height of a meteor falling to the Earth. The meteor starts at 100 km above the Earth's surface and falls at a rate of 20km per second. The x values represent the time in seconds and the y values represent the height of the meteor. What does the domain represent in context of the model?

Answer 1

The domain represents the time of motion of the meteor as it falls from 100 km height above the Earth's surface at a speed of 20 km

Explanation:

The given parameters from the question are;

The elevation of the meteor above the Earth's surface = 100 km

The rate at which the meteor falls = 20 km per second

The 'x' values represent the time in seconds and the 'y' values represent the meteor's height

Therefore, we have;

y = 100 - 20·x

The domain of a function is the set of inputs to the function

Therefore, the domain represent the time it takes the meteor to reach the given 100 km height above the Earth's surface

At the start x = 0 seconds

On the Earth's surface, y = 0, therefore;

0 = 100 - 20·x

x = 100/20 = 5

When the meteor just touches the Earth's surface x = 5 seconds

Therefore, the domain is 0 ≤ x ≤ 5.