Answer :
Answer:
(a)Grade =7.5% (No warning sign is needed)
(b)Rise =90 feet
Step-by-step explanation:
[tex]\text{Slope = }\dfrac{Rise}{Run}[/tex]
(a)
Rise = 63 feet
Run (Horizontal distance) = 840 feet.
[tex]\text{Slope = }\dfrac{63}{840}=0.075\\\\$Grade=Slope \times 100 = 0.075 \times 100 = 7.5\%[/tex]
A warning sign should not be posted since its grade is less than 8%.
(b)
Grade = 9%
Run (Horizontal distance) = 1000 feet.
Recall that:
Grade = Slope X 100
[tex]9 =\dfrac{Rise}{1000} \times 100\\\\9 =\dfrac{Rise}{10}\\\\$Rise = 9 \times 10 \\$Rise=90 feet[/tex]
The road rises 90 feet over a distance of 1000 feet.