Question

A highway engineer specifies that a certain section of roadway covering a horizontal distance of 2km should have a downgrade of 8%. Compute the change in elevation of this section of road. Use the slope formula.

Answer 1

Answer: ∆h = 0.16km = 160m

The Change in elevation is 0.16km

Explanation:

Given:

Change in elevation m= 8% = 0.08

Which means for every 100 units change in horizontal distance there would be 8 units change in elevation.

Horizontal distance of road x= 2km

Using the equation;

∆h = mx

Where ∆h = change in elevation

∆h = 0.08 × 2km

∆h = 0.16km = 160m

Answer 2

`0.16km`

Explanation:

A highway engineer wants to compute the change in elevation of a section of road. The horizontal distance of this section of road is 2km and downgrade is 8%

The slope formula is given by

`m=(rise)/(run)=(x)/(y)`

m = 8% = 8/100

run = y = 2km

`m =(x)/(y)`

`(8)/(100) =(x)/(2)`

`(2*8)/(100) =x`

`x=(16)/(100) =0.16km`

Verification:

`m=(0.16)/(2)= 0.08=8%`%