Answer:
A) A 9% downhill grade means that the decrease in elevation of the road over the segment is 9% of the change in Horizontal distance over the same segment. In other words, for every 100 horizontal feet the road descends 9 feet and the road has a slope of 0.09 vertical feet per horizontal foot.
Step-by-step explanation:
A Certain westbound U.S highway truck route near a river has a downhill grade of 9%
A) A 9% downhill grade means that the decrease in elevation of the road over the segment is 9% of the change in Horizontal distance over the same segment. In other words, for every 100 horizontal feet the road descends 9 feet and the road has a slope of 0.09 vertical feet per horizontal foot.
In other to make things clear, lets assume
for X = 1 , y = 9% = 0.09
for y = 9 , x = 9 / 0.09 = 100
slope = y/x = 0.09 / 1 = 0.09