We are told that the guidelines for a wheelchair ramp suggest that the ratio of the rise to the run cannot be greater than 1:12. We want to know if one of our ramps in our school or neighborhood follow the guidelines. To do so, consider the next example of a ramp with a slope equal to 0.07.
We need that the rise and run be no greater than 1:12.
Since the slope is described as the ratio of the rise and run, we can use the slope of the ramp to see if it satisfy the guidelines. Let's rewrite 1:12 as a quotient and then as a decimal to know the value of the guidelines.
This means that the slope of our ramp must be less than 0.08.
0.08 > 0.07
Therefore, our ramp follow the guidelines. This is just an example and there are many other possible scenarios.
Now, we will design a wheelchair ramp that will provides access to a building with a front door that is 2.5 feet above the sidewalk. Remember that the slope of the ramp has to be no greater than 1:12, or 112.
To follow the guidelines, the slope of this ramp have to be less than 112. We need to determine the minimum length of AB to satisfy these condition. To do so, remember that the slope is the ratio between the rise and run.
m=Rise/Run
In our case, the rise is the length of AC and the length of AB is the run. Let's write an equation where the slope of our ramp is equal to 112.
AC/AB= 1/12
Now, we will substitute AC= 2.5 into the above equation and solve it for AB.
