RTI ramp math...

[AJMBLAZER]

So I was out with my two buddies and their Jeep and Scout today. The Scout is a '69 800 that's all custom with a 350, TH400R4, Atlas (I think), and D44's on 35's. Suspension is a nitrogen charged air shock on each corner with links. He's got ridiculous travel. Made it all the way until the rear tire was coming up onto the ramp without lifting. I think he'd have rolled before he lifted actually.

At any rate, I know this means he got a 1000 but what we're trying to figure out is what degree the ramp is?
I have the distance straight to the ground of a fixed point, the distance from that point on the ground to the start of the ramp, the distance from the start of the ramp up to the first point, and obviously the one 90 degree angle we created. Can't remember enough algebra to figure out the angles.

The ramp was more than 20 degrees by a healthy margin.

 

[BGKYK5]

You don't need algebra, you need trigonometry.

tangent(angle)=(vertical measurement)/(horizontal measurement)

angle = inverse_tangent(vertical/horizontal)

Make sure you use an inverse tangent function that works with degrees (instead of radians).

 

[dremu]

Oh good lord it's basic trig =))

http://en.wikipedia.org/wiki/Sine#Sine

sin A is a/h, cos A is b/h.

Since you don't know A you actually want the arctangent, which IIRC the Windows calculator doesn't have, so I just start punching in values for the angle until I get about the right value =))

EDIT: Crap, beaten to the punch...

-- A

 

[AJMBLAZER]

Yeah yeah...I learned all this in Algebra 110 which dabbled in Trig. It was also 3 years ago and at age 30 I haven't used it since HS or this class.

Now to find that paper...


okay smertiepants:

a = 79"
h = 86"
b = 37"

Now gimme my angle before I embarrass my sunburnt, tired, slow thinking self trying to use my old TI-82! I'll come up with a negative number or something.

 

[dremu]

Yeah yeah...I learned all this in Algebra 110 which dabbled in Trig. It was also 3 years ago and at age 30 I haven't used it since HS or this class.

Now to find that paper...


okay smertiepants:

a = 79"
h = 86"
b = 37"

Now gimme my angle before I embarrass my sunburnt, tired, slow thinking self trying to use my old TI-82! I'll come up with a negative number or something.

I'm thinking you mean the horizontal side of the ramp was ~79" and the vertical was 37" ... if 'twas the other way 'round, it'd be a 65* ramp

As it is it's right about 25* (tan 25 = .466, whereas 37.79 = .468).

And you have nothing to whine about ... a buddy just reminded me that my 20th HS reunion is this summer.

-- A

 

[AJMBLAZER]

Thanks, 25 degrees it is.

Eh, my 10th was two years ago (2007) and I wasn't even invited.