A drainage slope of 5% equals what drop in 10 feet?

To understand how to calculate the drop given a drainage slope of 5%, it's important to grasp the concept of slope as a percentage. A slope of 5% indicates that for every 100 units of horizontal distance, there is a vertical drop of 5 units.

In this case, you need to determine the vertical drop over a horizontal distance of 10 feet. First, convert the drop percentage into decimal form (5% = 0.05). Next, to find out how much drop corresponds to 10 feet, multiply the horizontal distance by the slope:

Vertical drop = Horizontal distance × Slope

Vertical drop = 10 feet × 0.05 = 0.5 feet

To convert feet to inches (since there are 12 inches in a foot), you multiply the vertical drop in feet by 12:

0.5 feet × 12 inches/foot = 6 inches

Therefore, a 5% slope over a 10-foot distance results in a total drop of 6 inches, making this the correct answer. This calculation is fundamental for understanding drainage conditions in construction and landscaping, as proper slope design is critical for effective water management.