Question

FACTS:In 2010, the glacier was 1000 meters in length; it had retreated 255 meters in 15 years.Questions:1. Calculate the average annual rate of retreat of the glacier

Answer 1

Let's represent the given (length, years) as (x, y)

at time 0 year, the glacier is 1000 meters

at time 15 years, the glacier retreated 255 meters and that's 1000 - 255 = 745

so we have the points (0, 1000) and (15, 745)

Using the slope formula :

$m=\frac{y_2-y_1_{}}{x_2-x_1}$

where m represents the average annual rate of retreat.

$m=\frac{745-1000}{15-0}=\frac{-255}{15}=-17$

The average annual rate of retreat of the glacier is 17 meters per year