Steep slope

driving the other day in hilly country. when I got to the top of one hill, there was a very big sign that arned the other side was a 10% grade. It was steep.

How much is that in degrees ?

4.5... I think.

EDIT: Oops.

5.71?

http://en.wikipedia.org/wiki/Grade_%28slope%29

5.71

I remember climbing one of those in a box truck.. GVWR was 25,950.. I think we weighed 25,900. Climbing up out of pittsburgh in 2nd gear is no fun

How do you calculate % slope?

20° ... as best as I can remember from yrs ago as a surveyor ... some kind of relationship based on a straight up cliff (90°) equaling a 100% grade ... can't seem to make it work in my late night mind .... I'm sure there are more accomplished engineers on here that can throw more light on this than I can remember

Isn't it rise or fall per distance?

E.g. 10% would be 10 feet every 100 feet. 100% would be 45 deg.

yeah.... that sorta jogs what few memory cells are still doing a little work

makes more sense than the 90°=100% ...

Mmadness wrote: How do you calculate % slope?

shiny happy person pucker divided by possible knee blowout: beyond this it becomes an old man equation.

If you stand on a ski slope and you can reach out and touch the snow at shoulder height it is roughly 45 degrees. That's all I've got.

The entrance to Laguna Seca is 16%. Fun to go down with a loaded two-car trailer.

% slope, or grade, is the same thing as tangent of the angle, if you remember back to your high school trig - wait, do they still teach trig?

In reply to Jim Pettengill:

They tried with me, didn't click until I took vector mechanics.

The only thing I remember from trig was that the girl in front of me smelled like strawberries.

I've ridden a bicycle up slopes averaging over 11% and peaking near 20%. That's steep enough it feels like you'll fall over backwards if you stop. See Hog Pen Gap, outside Dahlonega GA. It sure felt like 45 degrees, but I'm sure it's less.

Percent grade to degrees conversion charts

and, whaddya know, 100% does equal 45deg

I've looked at that chart, and something just doesn't seem right ... I 26 between Hendersonville, NC and Spartanburg, SC has some pretty steep grades (I think the signs say something along the lines of 6%) and I promise you they are much steeper than the 3-4° that that chart shows ....

I dunno, but it sure seemed steeper than 6 degrees.

wbjones wrote: I've looked at that chart, and something just doesn't seem right ... I 26 between Hendersonville, NC and Spartanburg, SC has some pretty steep grades (I think the signs say something along the lines of 6%) and I promise you they are much steeper than the 3-4° that that chart shows ....

I've driven those same slopes and yessir it feels almost like driving down a cliff face.

Watkins Glen has a few of those nastys too.

iceracer wrote: I dunno, but it sure seemed steeper than 6 degrees.

The other angle, it's 90 -6 = 84 degree angle. That's steep!

Mmadness wrote: How do you calculate % slope?

someone probably hit it already but..

rise(height) / run(distance) x 100 = % slope

thats how us surveyors think of it, having to check driveway slopes for code requirements, handicap ramp slopes for ADA requirements

Go find your local road on hill and take two 12" rulers and level. Calculate slope/grade and find out that it's not as much as you would think...

I think railroads are limited to a 5% slope inmost cases - think about how shallow that really is.

cwh wrote: Watkins Glen has a few of those nastys too.

The hill down to the Falls Motel (past the hospital) is great for finding out if your trailer brakes work :)