Chapter 8.5, Problem 20WE

To determine

To find: the grade of road.

Answer to Problem 20WE

The grade of road is $14\%$ .

Explanation of Solution

Given:

The angle that the road makes with horizontal is $8°$

Calculation:

The grade of road is calculated as follows:

  $\begin{array}{c}\tan x=\frac{\text{Height}}{\text{Base}}\\ \tan 8°=\frac{\text{Height}}{\text{Base}}\\ \frac{\text{Height}}{\text{Base}}\approx 0.14\\ or,\\ \frac{\text{Height}}{\text{Base}}\approx 14\%\end{array}$

Thus, the grade of road is $14\%$ .