SOLUTION: 74. Road Grade When dirving down a mountain road, you notice warning signs indicating that it is a "12% grade." This means that the slope of the road is -12/100. Approximate the a

Algebra ->  Graphs -> SOLUTION: 74. Road Grade When dirving down a mountain road, you notice warning signs indicating that it is a "12% grade." This means that the slope of the road is -12/100. Approximate the a      Log On


   



Question 268506: 74. Road Grade
When dirving down a mountain road, you notice warning signs indicating that it is a "12% grade." This means that the slope of the road is -12/100. Approximate the amount of horizontal change in your position if you note from elevation markers that you have descended 2000 feet vertically.
I stuck I don't get it can you help. Thanks

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
One way to explain it is:
If you are driving down a 12% grade, You will aways be 12%
below where you would have been if you could have
driven on flat ground from where you started.
Say you descend 2 ft. You are 12% below what?
2+=+.12x
x+=+2%2F.12
x+=+16.67 ft from start
That's how far you would have driven on flat ground
Say you descend 20 ft. You are 12% below what?
20+=+.12x
x+=+20%2F.12
x+=+166.67 ft from start
That's how far you would have driven on flat ground
Say you decend 2000 ft. You are 12% below what?
2000+=+.12x
x+=+2000%2F.12
x+=+16666.67 ft from start
Also how far you would have driven on flat ground
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Suppose you are on a 1% grade and you descend 2000 ft.
If you had been on flat ground from the start, you
would have driven:
2000+=+.01x
x+=+200000 ft from start
The same thing works for hills, too
If I'm on a 1% grade going uphill, and I gained 2000 ft
vertically, where would I be if I had driven on flat ground?
2000+=+.01x
x+=+200000 ft from start -the same answer, but now I'm
looking down at where I started, instead of looking up.
Hope this helps.Drawing pictures is a good idea, too