Give reasons for the following statements:
(a) Railway tracks are laid on large sized wooden sleepers.
(b) It is difficult to walk on and.
(c) Walking bare footed on a pebbled path is painful.

Explanation

(a) This is done in order to spread the force due to weight of the train on a larger area and to reduce the pressure. This helps in preventing the yielding of the ground under the weight of the train.
(b) Sand is made of small loose particles which can yield easily under the weight of a person as the pressure exerted on them is large.
(c). While walking on a pebbled path, the entire weight of our body gets supported on the sharp edges of pebbles. So, as a result of reaction from a pebble, large pressure is exerted on our feet, which causes pain and discomfort while walking.