Question

1. a) how long will a section of railroad track be if it rises 6.8 metres for a run of 125.9 metres? b) what is the percent grade of the road?

Explanation:

Step1: Recall grade formula

The percent - grade formula is $\text{Percent Grade}=\frac{\text{Rise}}{\text{Run}}\times100\%$.

Step2: Identify rise and run

Given that the rise is $6.8$ metres and the run is $125.9$ metres.

Step3: Calculate percent - grade

Substitute the values into the formula: $\text{Percent Grade}=\frac{6.8}{125.9}\times100\%$.
First, calculate $\frac{6.8}{125.9}\approx0.054$.
Then, $0.054\times100\% = 5.4\%$.

Answer:

$5.4\%$