$this->bbcode_second_pass_quote('Niagara', '
')Cool! We arrive at a screaming 200km/h
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Gravity transit ?
Re: Gravity transit ?
by BlisteredWhippet » Mon 21 Aug 2006, 15:53:10
Scary...
But potentially useful... slow down the tram on the downslope to something reasonable through regenerative braking and produce electricity?
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Re: Gravity transit ?
by sciencegirl » Tue 22 Aug 2006, 10:29:24
We could even throw in some loop de loops for fun 
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Re: Gravity transit ?
by Licho » Tue 22 Aug 2006, 12:45:14
$this->bbcode_second_pass_quote('sciencegirl', 'I')t probably would have taken 5 hours had i walked the 10 kilometers.
Slow walking is about 5km/h, if you are in hurry you can comfortably maintain 6-7km/h .. so not 5 hours but more like 1 and half hour when walking.
Using bike, you can get there in couple of minutes.. and you won't sweat as much as after walking up to 37th floor (100m)...
Try walking up to some 10th floor to get a small glimpse of feeling of how is it to walk 100m up
Problem is that this idea wastes a lot of energy .. you need at least m*h*g of energy to get anything of the mass m to the height h on Earth.. That's at least 60kJ to get your body (60kg) up and 1000kJ for gondola (assuming it's car-like 1 ton stuff).
And you are going to waste (convert to heat) most of this energy in friction and by breaking on the way.
On the other side, if you take bike - we can do same oversimplication ignoring all friction by calculating only minimal energy expenditure to accelerate you to biking speed of 40km/h - it's just 1/2 m*v^2 = 3.7kJ and you don't have to pull gondola up..
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Re: Gravity transit ?
by Cran » Tue 22 Aug 2006, 12:59:11
a catapult with a really big rubber band could probably ping you 10 miles, and you wouldn't be limited to one finish point, you could go in different directions as well... 
might need a cushion to land on though or it might hurt a bit.
might need a cushion to land on though or it might hurt a bit.
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Re: Gravity transit ?
by Falconoffury » Tue 22 Aug 2006, 14:07:57
Bikes are good if you have a relatively flat road. If the conditions are rocky, and there are no roads, this gravity transport would probably work better.
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Re: Gravity transit ?
by BlisteredWhippet » Sun 27 Aug 2006, 01:24:27
$this->bbcode_second_pass_quote('Falconoffury', 'B')ikes are good if you have a relatively flat road. If the conditions are rocky, and there are no roads, this gravity transport would probably work better.
You know I've been biking hard recently and I moved to a very hilly area... its actually better in some ways because you save a lot of energy and take speed on the downhill parts. And uphills are made more tolerable with a hill-climbing sprocket.
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Re: Gravity transit ?
by Tanada » Sun 27 Aug 2006, 10:02:31
$this->bbcode_second_pass_quote('sciencegirl', 'Y')ou take the stairs, and the cost for the poles is a one time charge, but the cable would have to be replaced once a year for saftey reasons. Then you have a reverse gondela for the trip back.
The only difficult part is hoisting up the gondela for the return trip, but I am sure a pulley system would make it much easier.
As for what I would charge, maybe 1/2 of what bus fare is.
The only difficult part is hoisting up the gondela for the return trip, but I am sure a pulley system would make it much easier.
As for what I would charge, maybe 1/2 of what bus fare is.
I'm sorry to tell you this but tension is a direct function of cable streangth. You would need something like carbon nanotube cable in order to be able to put that much stress on it.
Go outside and look at high tension power cables, they are streatched to about 70% of breaking streangth. Then imagine that the poles are far enough apart that the center of the cable almost touches the ground. That spot would be where your 15 meter pole would have to be. You will soo realize it is way less than 10 miles, you might conceivably get 1 mile but no further.
The personal energy for climbing 330 steps (100 meters) has to be more than it takes me to walk a mile, though the idea of having two towers on opposite sides of a gorge or river might make it worthwhile. If that were my assignement I would have two towers as far apart as practicle with windmills on top for power. The gondola would act as a two loop elevator, you get on the gondola at ground level, ride to the top, coast down to the other tower bottom and get off. People going the other way get on when you get off, ride to the top and coast back across.
But for anything involving climbing stairs to coast down over level terrain you will burn more calories climbing the stairs than you would just walking the distance.
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To strive, to seek, to find, and not to yield.
Moved earth and heaven, that which we are, we are;
One equal temper of heroic hearts,
Made weak by time and fate, but strong in will
To strive, to seek, to find, and not to yield.
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