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Question
A solid weighs 32 gf in air and 28.8 gf in water. Find: (i) The volume of solid, (ii) R.D. of solid and (iii) The weight of solid in a liquid of density 0.9 g cm-3.
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Solution
Weight of solid in air , W1 = 32 gf
Weight of solid when completely immersed in water W2 = 28.8 gf
(i) Volume of solid = Mass / density of solid
= `32/10` = 3.2 m3
(ii) R.D. of solid = `W_1/(W_1 - W_2) xx "R.D. of water"`
R.D. of solid = `32/(32 - 28.8) xx 1`
R.D. of solid = 10
(iii) Weight of solid in liquid fo density 0.9 gcm-3 = W3
R.D. of solid = = `W_1/(W_1 - W_3) xx "R.D. of liquid"`
or , 10 = `32/(32 - W_3) xx 0.9`
or , `W_3` = 29.12 gf
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