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Help! House on the 3rd steepest city street in the COUNTRY - 34% grade - AWD? hp.? performance tires
It’s not a bad idea to carry a wooden chock around with you. They have pretty plastic ones too but the might get stolen. If I lived in a area where that was a concern, and it is, I would have them availabe.
@irlandes got a smart phone? You can pull your altitude information from its GPS function. Find the altitude at the bottom, then at the top of the hill. Measure how long the road is from the bottom to the top.
Now you have your hypotenuse and your vertical leg. Use the Pythagorean theorem to determine the horizontal leg.
Now divide the vertical leg by the horizontal leg. There’s your percent grade.
Good idea shadow. Grade is slope or rise/run converted to a decimal and written as a percent.
@BlackMountainDreamer that picture looking out from your front door is worth a thousand words. Wow!
Given your description of how the salesman abused the engine and transmission of the Rav4 in his run up your hill, I feel sorry for whomever later ends up buying that specific vehicle.
@Marnet - Exactly! I believe he did, in fact, damage the car. He looked about 15 to me but must have been at least 20. He got lost too and tore through the neighborhood a bit before getting to us. The Subaru salesman also brought the Crosstrek up in D and we ran through a number of very challenging maneuvers but it never gave off a burning odor. It’s no wonder people routinely blow transmissions up here - they just don’t realize they need a low gear. I think that’s because the majority of people cannot drive a manual anymore; if they did it would be totally obvious. It’s too short a run to ever hit 2nd.
...that picture looking out from your front door is worth a thousand words.
…or $2,000,000.
;-]
@insightful please point me to the publication where I can get paid $2,000 a word. I could use a new career. 
That is not how you find the angle of the grade. Yes you can use a 10’ 2x4 or use your GPS. If you use your GPS and your odometer, then dividing the altitude difference by the distance traveled will give you the sin (sine) of the angle, not the angle itself. You can look up the angle on a sin table or just do an inverse sin on your calculator.
For example, if your drove .5 miles and the GPS says you rose 900 feet, that would be 900/2640=.34 which is about 20°.
If you use the 2x4, then the function you use is tangent. So if the board held level is touching ground on one end and is 33" off the ground at the other, you have 33/120=.275. That corresponds to an angle of around 15.4°.
A 34° angle has a tangent of .6745 which would mean the end of the 2x4 would have to be almost 81" off the ground or a .5 mile drive would have to rise 1476 feet.
I didn’t get it done today. a short trip to the dentist turned into a two hour wait.
As far as the math I had trigonometry, and still have my Burington’s Handbook. And, a TI scientific calculator. And, C and C++ and Fortran compilers in my computers (free with Linux.) I am sure I can handle it once I get the data. Heh, heh.
My builder was using my level today. And, when he went to lunch, my wife needed a ride downtown.
I once taught a class on GPS to a group of sugar cane inspectors from Cordoba, Vera Cruz in Mexico. They were assigned the task of producing dimensions of all farm lots of sugar cane in their county (municipio). A formidable task.
They had a boss who was a brilliant engineer. She wrote a program which took the GPS coordinates and automatically converted it to acreage. (Not in Mexico, but I don’t know how to say hectarage…)
I taught them how to mark the coordinates.
But, civilian GPS simply isn’t that accurate. By law civilian receivers are prohibited from using the entire signal so there is a built-in error of a meter or two.
Civilians, most commonly surveyors, came up with differential GPS. They made radio transmitters which also received the standard GPS signal at a known location, and the differential transmitter transmits an error signal as the GPS signal deliberately shifts things around.When you feed the error signal into the differential surveyor’s receiver, this brings the error back to nearly zero.
The government requires the differential signal to be controlled by the military so in case of threat the error signal can be turned off and the zero error goes back to normal.
I did get a quick look as I drove by the street. It is not a single line. The slope changes in several places.
And, I forgot to mention that the buildings are close enough to the rather narrow street there would probably not be enough satellites visible to give full accuracy even for civilian GPS.
When I leave my house and walk up the big hill, GPS shows I have moved horizontally 4000 feet, and gone up 400 feet. (If I remember correctly.)
Maybe the house and the view is ok for some but my subjective view says that house would be listed for sale and I’d gone for flatter ground. Just my personal preference.
Half a bottle of port and getting the feet crossed up could mean a long painful roll.
On the positive side, I would imagine the crime rate is low there. Any criminal would be worn out by the time they got up there and too tired to break in… 
Blackmountain, if auto manufacturers are trying to convince us that their auto shifting devices are so much better than the diy units that they are worth the extra thousand dollars, I would expect it to keep it in first, automatically, without any input from me.
The Subaru was probably hunting between high and low gear as in the Toyota. But the gear spacing in the Subaru was so much closer that it probably wasn’t noticeable.
@Ir,some countries are amazed that Americans live in wooden houses,when I look at pictures of tornado damage I wonder too.But a lot of times,there is no worry about Heirloom quality(I hear"it will last me out")when I see a shoddy job
And you are welcome about the simplified grade checking apparatus,I guess on site GPS units use something else to be accurate(because they are used for final grading) John Q Public,gets GPS with a deliberate error built in(no reason to wonder why with the proliferation of drones and border hopping weapons{I dont want some nut crashing a drone into my bedroom}
Good math.does save a lot of steps and it seems ,trig has a lot of practical apps,Geometry should probaly be a required subject(at least the easily grasped,ever useful parts)
“A 34° angle has a tangent of .6745 …”
@Keith, the OP’s road is a 34% grade, not a 34° angle.
That is not how you find the angle of the grade.
I know that, but he asked how to find the percent grade, not the angle.
@chunkyazian - the fact that he hit almost 4000 rpm is proof enough that he moved out of 1st and into 2nd - automatic transmissions seem to limit 1st gear to starts but anyone who has driven a manual on steep city streets knows 1st is the only gear to be in unless you can maintain 20mph. Very few traffic situations on the steepest hills here allow those speeds. There are pedestrians crossing, construction lane closures, people braking in their search for parking, drivers slowing traffic to parallel park. . . The Toyota shifted and it shouldn’t have - the final ascent to our house from a perfectly flat starting point is rapid and short, meaning the distance to cover isn’t even close to being long enough to justify shifting into 2nd. At the point where you’d have enough speed to even think about shifting you’d have reached our driveway and would be forced to stop. I believe driving up here in D is a mistake in most cars.
the fact that he hit almost 4000 rpm is proof enough that he moved out of 1st and into 2nd -
Not really. I routinely hit redline in my automatic TL, and that’s at 6800. If the accelerator is pressed down hard enough, the transmission will significantly delay its shift.
Hopefully without giving off a strong odor of burning things up. . .
A heavier duty trans oil cooler would be a Good Thing.
But, civilian GPS simply isn’t that accurate. By law civilian receivers are prohibited from using the entire signal so there is a built-in error of a meter or two.
Your information is outdated. The SA feature was turned off back around 2000 and the feature will not even be included in the hardware for GPSIII. Augmentation allows for high degree of precision. Where I work, we design and build critical components for the US, European and Japanese constellations and have been doing so since their inceptions. We are delivering first prototypes for GPSIII now…