The American with Disabilities Act (ADA) requires that the slope of a wheelchair ramp be no greater than 1:12. Which of the following is the minimum length of a ramp needed to provide access to a door that is 5.2 feet above the sidewalk?
A.
52 feet
B.
148 feet
C.
32.2 feet
D.
62.4 feet
The Correct answer and Explanation is:
To determine the minimum length of a wheelchair ramp needed to provide access to a door that is 5.2 feet above the sidewalk while adhering to the Americans with Disabilities Act (ADA) requirement for a slope of no greater than 1:12, we can use the ratio of rise to run.
The slope of 1:12 means that for every 1 unit of vertical rise, there must be at least 12 units of horizontal run. Here, the rise is 5.2 feet. Therefore, we can calculate the minimum length of the ramp as follows:
- Understanding the Slope: The slope of 1:12 can be expressed in mathematical terms. If ( R ) is the rise (vertical height) and ( L ) is the length of the ramp, the relationship can be written as:
[
\text{slope} = \frac{R}{L} \implies L = 12 \times R
] - Substituting the Rise: In this case, ( R = 5.2 ) feet. Plugging this value into the equation gives:
[
L = 12 \times 5.2
] - Calculating Length: Performing the multiplication:
[
L = 12 \times 5.2 = 62.4 \text{ feet}
]
Thus, the minimum length of the ramp required to meet ADA standards for a rise of 5.2 feet is 62.4 feet.
Conclusion: Therefore, the correct answer is D. 62.4 feet. This calculation illustrates the importance of designing ramps that meet accessibility standards to ensure that individuals using wheelchairs can navigate changes in elevation safely and comfortably. A ramp that is too steep can create challenges for wheelchair users and may increase the risk of accidents. By adhering to the 1:12 slope ratio, designers can provide equitable access to all individuals, promoting inclusivity in public spaces.