Why the railway track are laid on large sized wooden or iron sleepers?
(SHARANYA posted this question)
Trains have huge masses and rails are narrow. Therefore if they are directly put on earth, they will sink down due to the extreme pressure it would exert on earth when run over by the train. So they are laid on wooden or iron sleepers of large area so that pressure on earth is reduced.
Pressure = Force /Area.
As area increases pressure decreases.