How the train is moving on rails with both wheel and rails are smooth and there is no concept of friction?

Answer 1

trains are following the engine wagon, there are five or six pairs of wheels aligned by five or six axles mounted to the bottom of the engine.

there are also similar wheels and axle assemblies on the bottom of individual coaches or wagons.the engine wheels are given a rotational torque load and though they are smooth they are rotating within the axle since the rotation torque is applied in the engine, is very much higher than the force required to slide. though the initial motion of the carriage wheels start with a slight sliding and before stopping the engine by applying breaks there will not be a sudden stop because of lesser friction the wheels will slide to a halt which will give a screeching sound.

Answer 2

The amount of static friction depends on the normal force at the point of contact. This in the case of locomotive is high due to its weight. Thus the frictional opposing force generated for movement is high (even though the co-efficient of friction may be low due to smooth surface) enough to keep the wheel touch point in place, there by causing rolling action.

Hence the train moves.

Once started it is the dynamic friction that comes into play, the smooth surface produces less dynamic friction, giving high efficiency for the system as such.

Answer 3

Perhaps you are thinking of the assertion that "rolling" friction for trains is negligible. That is, the friction in the bearings of the wheels is pretty much ignorable (for 1st order calculations anyway).

Naturally, the friction between the wheel and the track must exist or the wheels would slip and the train could never get started!

Answer 4

There is friction between drive wheels and rails. Metal against metal has friction, also tremendous weight of locomotive. However, if you would put grease or oil on rail, then train could not move.

Answer 5

There is sufficient friction. A locomotive weighs about a hundred tons. The steel of the wheels and rails is not absolutely smooth, and it deforms under the weight.

Answer 6

please also bare in mind (it can be easily shown with a diagram) that friction for object in movement is greater than the friction in rest. you can visualize old movies with steam engines while the the wheel of the train where spinning but the train did not move as it was supposed since the friction was not enough to transfer the force and affect motion. friction in a nessecity in order to move (at least for trains).

Answer 7

Take a closer look at the wheels and the rails.You will find a lot. The problem is with the way you are taught basic concepts of Physics.

Answer 8

The weight of the train is so great that you do not need any more friction.

Answer 9

The weight of the train is so great that you do not need any more friction.

Answer 10

the heavy weight of the train causes the wheels to bend a little.which causes a shift in the normal reaction of ther rails.As a result, a net torque is produced and this torque is reuired for rotation of wheels.