Question

What was Mike's average rate of descent over his last three hours?

Answer 1

Answer:

The average rate of descent over the last 3 hours is 1000 ft/h.

Step-by-step explanation:

Rate of Change

It's usually referred to as to the variation that one magnitude has in reference to another. The reference magnitude can be time t. The rate of change is calculated as the slope of the curve that represents the function.

The image shows the variation of Mike's height above sea level in feet with time in hours. We need to calculate the rate of change in the last three hours (from 7 to 10).

The rate of change can be calculated with the slope of the line, which formula is:

$\displaystyle m=\frac{h_2-h_1}{t_2-t_1}$

Let's pick two points (7,4000) (10,1000):

$\displaystyle m=\frac{1000-4000}{10-7}=\frac{-3000}{3}=-1000$

$m=-1000\ ft/h$

Note the rate of change is negative, which means the height is decreasing.

The average rate of descent over the last 3 hours is 1000 ft/h.