Elasticity is a mechanical property of matter. For example, we have a 10-meter rubber piece. Now after we pulled the piece of rubber, the rubber will be lost and its original length and width. Suppose now the length of the rubber has reached 30 meters. Now we have left the rubber and if the rubber comes back to its old state then this property is called elasticity. Due to elasticity, two things are produced that is strain and stress Here the original length of the rubber was 10 meters and after applying a force it turned to 30 meters. So how much rubber has been deformed 20 meters. If we calculate a change in one meter then answer will be 2. So what is this 2? this 2 is ratio is every unit change and this ratio is called strain. Now There is a question here that when we are pulling this rubber, then it is going to be deform. Because we are pulling it but when we are leaving it, then it is going back to its original state So the question here is how did it come back, we j