Question

Give examples to explain the difference between changes that can or cannot be reversed.

Answer 1

To explain the differences between changes that can or cannot be reversed, some examples are given below:

(i) If we inflate a balloon, the size and shape of the balloon undergo a change. However, the original size and shape of the balloon can be obtained back by allowing the air to escape from the balloon. This means that the change that occurs by inflating a balloon can be reversed. But, if the balloon bursts after being inflated, then its original size and shape cannot be obtained back. Thus, in this case, the change cannot be reversed.

(ii) If we fold a piece of paper, then the shape and size of the paper undergo a change. In this case, the original shape and size of the original paper can be obtained back. Thus, this change can be reversed. However, if we cut the piece of paper, the change in the shape and size of the paper cannot be reversed.

(iii) After we roll out a chapatti from a ball of dough, the chapatti can be converted back into a ball. Thus, the change occurring here can be reversed. But, if we cook the chapatti on a Tawa, then it cannot be converted back into a ball of dough. Thus, the change is irreversible.