2007-04-14 16:51:19 · 5 answers · asked by Mufaddal Kazi 3 in Science & Mathematics ➔ Engineering
There are several things going on with trains on the tracks.
First off, there is friction. The train running gear (wheels) are metal and the tracks are also metal. Just because they look smooth does not mean they don't have friction. The train is so heavy, and the area of contact between the wheelsets and the tracks so small, that a very large force is being pressed down on the contact area between the two. This is what allows the friction of the two metals to be great enough for the train to have "traction" on the tracks. The other answer is also partially correct, the metal used has a coefficient of fraction.
The wheelsets also are not completely flat but are ridged, this and their ability to rotate beneath the train keep it centered on the tracks.
The majority of modern trains today have diesel motors that are used to generate electricity which then powers electric motors on the drive wheels.
This should cover most of the frictions involved.
2007-04-14 17:15:58 · answer #1 · answered by FourWheelDave 3 · 0⤊ 0⤋
Trains stay on track because they follow directions. Trains do not need friction to generate power. Trains heading south run down hill by gravity. You can see this whenever you put a hotwheels car on top of a globe. To go back north they use the Coriolis force which is stronger closer to the Equator. This usually works in a circle , but the engineer has a linear accelerator in the front which converts the energy to a straight line. To go from east to west the centrifugal force is used. Because this is also stronger in the south trains run faster in Georgia than they do in New York. This is OK because there is less stuff in the way, like people. Trains used to have cow catchers on the front. If they could catch a cow, they hooked her up to pull the train. The cows pulled real hard and farted a lot which caused Global Warming, so they quit doing it.
2007-04-15 02:11:33 · answer #2 · answered by Bomba 7 · 0⤊ 0⤋
Go back and look again. Pay particular attention to a thing called 'coefficient of static friction'.
HTH
Doug
2007-04-14 23:55:43 · answer #3 · answered by doug_donaghue 7 · 1⤊ 0⤋
even though the coefficiant of friction is small the weight provides enough friction!!!
2007-04-15 02:34:00 · answer #4 · answered by Gene 1 · 0⤊ 0⤋
Huh?
You think steel on steel has no friction? Go get two pieces of steel and see how poorly they slide against each other.
2007-04-15 00:09:56 · answer #5 · answered by Anonymous · 0⤊ 0⤋