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Question
A solid weighs 105 kgf in air. When completely immersed in water, it displaces 30,000 cm3 of water, calculate relative density of solid.
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Solution
Weight of solid in air =105 kgf
Volume of solid = Volume of water displaced = 30000 cm3
= 30000 x 10-6 m3 = 0.03 m3
pw = Density of water = 1000 kgm-3
Wt. of water displaced by solid.
`"V"rho_"w""g" = 0.03 xx 1000 xx "g" = 30 "kgf"`
R.D. of solid = `"Weight of solid in air"/"Weight of water displaced by solid"`
`= 105/30 = 3.5`
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