Slope of descent, given change in elevation and hor. dist.

[KV]

Driving down a mountain, Tom finds that he has descended 1800 ft in elevation by the time he is 3.25 miles horizontally away from the top of the mountain. Find the slope of his decent to the nearest 100th.

The equation is c=mx+b but I cannot figure out the equation as to what is where.

 

[soroban]

Re: Slopes

Hello, KV!

Driving down a mountain, Tom finds that he has descended 1800 ft in elevation
by the time he is 3.25 miles horizontally away from the top of the mountain.
Find the slope of his decent to the nearest 100th.

Why are you working with the equation of a line?
They asked for the slope (only).

Note that 3.25 miles = 17,160 feet.

          *
          |     *
          |           *
     1800 |                 *
          |                       *
          |                             *
          *-----------------------------------*
          : - - - - - 17,160  - - - - - - - - :

His "rise" is -\(\displaystyle 1800\) . . . his "run" is \(\displaystyle 17,160\).

Therefore, the slope is: \(\displaystyle \:\frac{-1,800}{17,160} \:=\:-0.104895105 \:\approx\:-0.10\)

 

[KV]

Thanks soroban. I did not think of changing the miles to feet. I was looking for a starting point to get me headed in the right direction. Now I will always remember if one is in a different form I have to put them into an agreement.