% grade. What does it really mean?

[giant_mtb]

Nothing major, just wondering why they decided to use a percentage system instead of, well, angles for the denotation of hill angles.  I may be wrong, but it is my understanding that they took some maximum angle and divided it into 100 pieces, giving the percentile system.  For example, the "max" angle may be vertical, 90 degrees (100%).  A 7 degree decline would be a ~7.8% grade.

Is that how it works?  If it is, what angle are they dividing into pieces?  Why didn't they just use degrees?

[sportyaccordy]

I thought it was just amount of height per unit length of width traveled in percentage form. Meaning a 45 degree angle would be 100% grade, etc... it's probably not that though.

[giant_mtb]

Perhaps. Makes more sense than what I thought it was.

[SVT_Power]

I thought it was just amount of height per unit length of width traveled in percentage form. Meaning a 45 degree angle would be 100% grade, etc... it's probably not that though.

that's what i thought it was 

[Tave]

C'mon peoples. This is easy.

Grade is Slope. Slope is rise over run. Percent Grade = Slope * 100

I thought it was just amount of height per unit length of width traveled in percentage form. Meaning a 45 degree angle would be 100% grade, etc... it's probably not that though.

Exactly.

[GoCougs]

Yes - Sporty has it correct - 8% grade = 8 ft vertical change for 100 ft of horizontal travel.

To really impress the girls, divide % grade by 100 to get the tangent of the angle, and then take arc tangent to get the angle itself; arc tan (.08) = 5.08 degrees.

[sportyaccordy]

Yes - Sporty has it correct - 8% grade = 8 ft vertical change for 100 ft of horizontal travel.

To really impress the girls, divide % grade by 100 to get the tangent of the angle, and then take arc tangent to get the angle itself; arc tan (.08) = 5.08 degrees.

Totally unnecessary

[S204STi]

Yes - Sporty has it correct - 8% grade = 8 ft vertical change for 100 ft of horizontal travel.

To really impress the girls, divide % grade by 100 to get the tangent of the angle, and then take arc tangent to get the angle itself; arc tan (.08) = 5.08 degrees.

Do you carry a scientific calculator to impress the gals?

[bing_oh]

Do you carry a scientific calculator to impress the gals?

They do so love to fondle his pocket protector.

[S204STi]

They do so love to fondle his pocket protector.

Seriously though, I'm just jealous of his math skills.  I am worthless with math any more complex than the basics like adding, subtracting, multiplying and dividing.  Geometry got be bad back then, and it still gets me now.

[MX793]

Do you carry a scientific calculator to impress the gals?

Scientific calculator?  You're not going to impress anybody with one of those trinkets.  Now a graphing calculator, that'll get you some respect.

[Laconian]

The honeys are all up ons over my RPN.

[S204STi]

Scientific calculator?  You're not going to impress anybody with one of those trinkets.  Now a graphing calculator, that'll get you some respect.

[GoCougs]

They do so love to fondle his pocket protector.

You mean, fondle The Canon:



And no, Sporty, it wasn't unnecessary; "grade" is the tangent of the angle, a function without which one cannot find the angle, which is exactly what the OP was trying to do.

[93JC]

Not just 'a Canon'? The Canon?

Oooooh...

[AutobahnSHO]

lawl

I sold my TI-85 years ago-

[sportyaccordy]

Cougs I was just joking.

[GoCougs]

Cougs I was just joking.

Okay, I just thought maybe you were still hating me...

[VTEC_Inside]

lawl

I sold my TI-85 years ago-

Still have mine... I put Tetris on mine back in College. :)

[sportyaccordy]

Okay, I just thought maybe you were still hating me...

That hasn't changed.

[BimmerM3]

I'm still rockin' the TI-83 Plus.

[Eye of the Tiger]

I have The Pirate's TI-89.
But I don't know how to use half of the shit

[93JC]

I'm still rockin' the TI-83 Plus.

Mine's kicking around somewhere.

[SVT_Power]

I have The Pirate's TI-89.
But I don't know how to use half of the shit

damn you

[Eye of the Tiger]

damn you

I'll sell it to you for $199.99.99.

[MX793]

I'm still rockin' the TI-83 Plus.

I've got an original TI-83 from before the "plus" model ever came out.  I remember when the Plus version came out and everybody was like "ooh, look, it's the Plus version so it's better" only to find out that all of the games for the regular TI-83 like pong and tetris didn't work on it.

[r0tor]

Do you carry a scientific calculator to impress the gals?

To really impress the girls, you tell them the tangent or slope of the incline is equal to the coefficient of friction needed to stay on the incline  

[bing_oh]

Seriously though, I'm just jealous of his math skills.  I am worthless with math any more complex than the basics like adding, subtracting, multiplying and dividing.  Geometry got be bad back then, and it still gets me now.

I'm right there with ya. My sister's a high school math tecaher, teaching things like advanced algebra and trig. Me, I can't figure out the tip at a restaurant without the tip calculator on my cell phone.

[93JC]

To really impress the girls, you tell them the tangent or slope of the incline is equal to the coefficient of friction needed to stay on the incline  

Have you tried the old "I wish I were a derivative so I could lie tangent to your curves" pickup line?

[hotrodalex]

I'm right there with ya. My sister's a high school math tecaher, teaching things like advanced algebra and trig. Me, I can't figure out the tip at a restaurant without the tip calculator on my cell phone.

I just take 10% and add a bit to it.