Raman was waiting at a tyre puncture repair shop to get his bicycle tube repaired. There is a large pond of water a little distance away from this shop. Some children were playing near the pond. Raman saw a five year old child fall into the pond accidently while playing. The child was drowning in pond water and screaming for help. Raman took a big, inflated car rubber tube' which was lying in the shop and immediately threw it towards the drowning child in the pond. He shounted asking the child to cling to the inflated tube and hold on to it strongly till the help arrived. Raman then made a telephone call to Fire Brigade from his mobile phone. The Fire Brigade reached within ten minutes and the firemen brought the drowning child out of the pond safely. Everybody praised the efforts the efforts of Raman and firemen.
(a) What happens when an inflated car tube is thrown in water of the pond? Why?
(b) Why did Raman throw an inflated car rubber tube towards the drowning child and ask him to hold on to it?
(c) Which principle is made use of by Raman in saving the drowning child? State this principle.
(d) What values are displayed by Raman in this episode?

Explanation

(a) When an inflated car rubber tube is put in water, if floats in water. This can be explained as follows: The inflated rubber tube contains a lot of compressed air in it. Now, air is a very, very light substance. So, due to the presence of lot of air in it, the average density of inflated car tube is much less than the density of water. Since the average density of inflated car tube is less than that of water, therefore, the inflated car tube floats in water.
(b) Raman threw an inflated car rubber tube towards the drowning child and asked him to hold on to this inflated tube because the inflated rubber tube would remain floating in water and, alongwith it, the child would also remain floating in water and not get drowned. Actually, when the child clings to the inflated rubber tube, then (due to his weight) more portion of inflated rubber tube gets submerged in water, it displaces more water and hence the upward buoyant force increases. This greater upward buoyant force keeps the inflated rubber tube and the child holding it, both afloat on the surface of pond water (and prevents drownings).
(c) Raman made use of the principle of flotation. According to the principle of flotation: An object will float in a liquid if the weight of object is equal to the weight of liquid displaced by it.
(d) The various values displaced by Raman are (i) Knowledge of principle of flotation (ii) Application of knowledge in everyday situations (ii) Presence of mind (in throwing an inflated tube immediately towards the drowning child) (iv) Responsible citizen (in calling Fire Brigade to rescue the following child), and (v) Helping nature (in saving drowning child).