The main reason why wheelchair ramps are used to move people up a staircase is because it has a high mechanical advantage which leads to a greater efficiency in moving people up the staircase.
The mechanical advantage of the ramp is calculated as follows;
[tex]M.A = \frac{L}{h}[/tex]
As the length of the ramp increases, people will be move up to a greater distance up the staircase.
Thus, the main reason why wheelchair ramps are used to move people up a staircase is because it has a high mechanical advantage which leads to a greater efficiency in moving people up the staircase.
Learn more about mechanical advantages of ramps here: https://brainly.com/question/200179