A 30 foot long driveway has a 5% slope from one end to the other. What is the rise or change in grade?

To calculate the rise or change in grade for a driveway with a slope, you can use the formula that relates the slope percentage to the rise and run. The slope percentage tells you how many units of rise correspond to a certain number of units of run.

In this case, a 5% slope means that for every 100 units of horizontal distance (run), there is a 5 unit change in vertical distance (rise). To find the rise over a 30-foot driveway, you can first convert the slope percentage to a decimal for calculation:

5% = 0.05

Now, multiply the decimal slope by the length of the driveway (in feet), which is 30 feet:

Rise = Slope × Length

Rise = 0.05 × 30 feet

This calculation results in:

Rise = 1.5 feet

Since there are 12 inches in a foot, you can convert the rise to inches:

1.5 feet × 12 inches/foot = 18 inches

This calculation confirms that the change in grade for the driveway is indeed 18 inches, demonstrating the appropriate application of slope calculations in excavation and grading practices.