Question

Chelsea walked up a road that has 15% grade to get to her favorite store. That means the slope of the hill was 15/100. At what angle does the road come up from the ground ?

Answer 1

`8.53\°`

Explanation:

we know that

The grade of a road can be thought of as rise/run, and you usually see it as a percentage.

So, a 15% grade is the same as a grade of 15/100; for every 15 units the road goes up vertically, it goes 100 units horizontally

see the attached figure to better understand the problem

Let

`\theta` -----> angle does the road come up from the ground

The tangent of angle theta is equal to the ratio of the opposite side by the adjacent side

`tan(\theta)=(15)/(100)`

`\theta=tan^(-1)((15)/(100))=8.53\°`