When you take the Columbia Ice Field Ice Explorer (see picture below) in Jasper National Park, you go down a very steep hill. At one point, it is 18 degrees. What percent grade is that?
Solution to the Problem:
The answer is 32.5%.To determine the percent grade, take the tangent of 18 degrees, which equals .3249 or 32.5%.
However, James Alarie wrote," I'm finding two different definition of road grade. One says it is rise over run and a 45 degree hill would have a 100% grade. Another says it is vertical height difference divided by the length of road involved.
The rise-over-run definition would then use the tangent of the angle and the answer would be: tan(18)=0.3249 = 32.49%.
The height-per-road-length would use the sine of the angle and the answer would be: sin(18)=0.3060 = 30.60%."
Correctly solved by:
| 1. James Alarie | Flint, Michigan |
| 2. Alex Houskeeper |
Mountain View High School, Mountain View, Wyoming |
| 3. Chad Fore | Gate City, Virginia |
| 4. Braydon D Saxton |
Mountain View High School, Mountain View, Wyoming |
| 5. Keith Mealy | Cincinnati, Ohio |
| 6. Chris Stringer |
Mountain View High School, Mountain View, Wyoming |
| 7. Dalton Hereford |
Mountain View High School, Mountain View, Wyoming |
| 8. Dane Covington |
Mountain View High School, Mountain View, Wyoming |
| 9. Ryan Woody |
Mountain View High School, Mountain View, Wyoming |
| 10. Austin Smith |
Mountain View High School, Mountain View, Wyoming |
| 11. Morgan Harris |
Mountain View High School, Mountain View, Wyoming |