Question

A stream is flowing down a slope into a larger river. The elevation of the head of the stream is 1,776 feet above sea level. The elevation of the mouth of the stream is 1,298 feet. The distance between those two points is 15,098 feet. What is the gradient of the slope the stream is flowing over in ft/mi?

Answer 1

-167.2 ft/mile

Explanation:

The "rise" is 1298 -1776 = -478 ft. The run is given as 15,098 ft, so the slope is ...

slope = rise/run = -478/15098 ≈ -0.0316598

For 5280 feet in 1 mile, that rate of change amounts to ...

-0.0316598×5280 ft ≈ -167.2 ft . . . per mile