Question

why are iron rails of railway track fixed over wide wooden or concrete sleepers

Answer 1

iron nails are fixed over wide wooden or concrete sleepers because metals have a tendency to expand on heating so if nails would be fixed over any metal then the metal would expand by the heat of the sun and then the nail would become loose which could cause problems in the track

Answer 2

and even when the train moves the vibration released by the train would be too high . if the earth absorbs it there would be massive earth quakes. to prevent it the concreteflooring is used ,florring will absorb it and quake is prevented