Is there such thing as a train which can run on gravity and it does not require any energy to run?

Question

this train only works when it goes up and down hills. If you find anything interesting about this topic then post it.

Answer 1

Yeah, it's called a roller coaster.  Unfortunately, you need a motor to get it to the top of the hill first.

Answer 2

only a small one .. a sled it goes down hill..

Answer 3

Cliff railways that use the weight of water.

eg the Centre for Alternative Technology http://www.cat.org.uk/vt/vt_content.tmpl...

"The Centre's water-powered cliff railway can take 17 adults at a time up (or down) the 60 metre incline. It operates on the principle of 'water-balancing': the two carriages are connected by cable via a winding-drum at the top; water is run into a tank beneath the upper carriage until it is just heavier than the lower carriage and its passengers; then the parking brakes are released and gravity does the rest. It is one of the steepest cliff-railways in Britain, with a 35o slope. It has an unusually wide gauge of 1.6 metres, and the carriages are set to travel at 0.61 metres per second. The speed is controlled by a hydraulic pump combined with a regenerative braking system, allowing the surplus energy from the hydraulics to pump some of the water back to the top."

Answer 4

No...

Your energy source would BE gravity.

And not that I know of- at least currently.

Answer 5

You are asking about a "perpetual motion machine", which violates the "conservation of energy" law of physics.  Therefore, it doesn't and can't exist.

Answer 6

Maglev technology is about as close as we can get for now...unless you have a better idea..and if so...I would like to invest.

http://www.calmaglev.org/default.php?get...

Answer 7

I dont think that trains run on gravity, but that reminded me of rollercoasters.