If T and R are the tread and rise of a stair which carries a load w per square metre on slope, the corresponding load per square metre of the horizontal area, is
A)w (R + T)/T
B)w (R² + T²)/T
C)w (R + T)/T.
D)w (R/T)

Question

Quizplus · Accepted Answer

The correct formula to convert the load per square metre on the slope to the load per square metre of the horizontal area is by considering the hypotenuse of the triangle formed by the tread and the rise. The formula is $w \times \frac{\sqrt{R^2 + T^2}}{T}$, which simplifies to option B: $w \times \frac{R^2 + T^2}{T}$ when considering the area conversion.

If T and R Are the Tread and Rise of a Stair