Rajan went on a World Tour with his family during the summer holidays. Actually, it was a group tour consisting of 40 persons arranged by a leisure travel company. Thomas Cook'. Today the whole group was taken to a sea that lies between Is real and Jordan, and has become a famous tourist spot. On reaching the seashore, everyone was surprised to see a person floating in this sea water in the sitting position and even reading a newspaper in this position. The Guide, Mr. Jose, who accompanied the group, asked if anyone could explain this strange observation. Rajan is a science student of class IX. Rajan took a little of sea water in his palm and put it into his mouth for a moment (and then spit it out). After thinking for a while, he could answer Mr, Jose's question. Rajan then explained everything very clearly to all the persons in the group. Everyone appreciated his knowledge of science.
(a) What is the name of the sea which lies between Isreal and Jordan?
(b) Why is this sea called by this name?
(c) What did Rajan find when he put a little of water from this sea into his mouth for a moment?
(d) Explain why, a person can float in this sea water in the sitting position.
(e) Why is it not possible to float in sitting position in the water of Indian sea?
(f) What values are displayed by Rajan in this episode?

Explanation

(a) Dead sea.
(b) It is called 'Dead sea' because due to its very high salt content, no living things (plants and animals) can exist in it.
(c) When Rajan put a little of this sea water in this mouth, he found it to be extermely salty (having a lot of salts dissolved in it).
(d) The water of Dead sea has an extremely large amount of salts dissolved in it. Due to large amounts of dissolved salts, the density of this sea water is very,very high. Because of extremely high density, the water of Dead sea exerts a very,vert large upward 'buoyant force' (or upthrust) that makes a person float in it sitting up.
(e) Indian sea water contains much less dissolved salts than the water of Dead sea. So, the salty water of Indian sea exerts much less upward 'buoyant force' (or upthrust) which is not able to support the weight of a person in sitting up position.
(f) The various values displayed by Rajan in this episode are (i) Awareness of buoyant force exerted by liquids (ii) Knowledge of factors affecting the magnitude of buoyant force (such as density of liquid) (iii) Application of knowledge in solving problems, and (iv) Analytical mind (in checking sea water).