A PIECE OF BRASS WEIGHS 12.9 GRAMS IN AIR .WHEN COMPLETELY IMMERSED IN WATER IT WEIGHS 11.3GRAM.WHAT IS THE MASS OF THE COPPER CONTAINED IN THE ALLOY?RELATIVE DENSITY OF COPPER AND ZINC ARE 8.9 AND 7.1 RESPECTIVELY. 

Asked by M.s.srinidhi21 | 19th Oct, 2014, 04:47: PM

Expert Answer:

begin mathsize 14px style mass space of space brass space in space air equals 12.9 space straight g mass space of space barss space in space water equals 11.3 space straight g mass space of space water space displaced equals 13.9 minus 11.3 equals 1.6 space straight g relative space density space of space copper equals 8.9 relative space density space of space zinc equals 7.1  Relative space density equals fraction numerator density space of space substance over denominator density space of space water end fraction rightwards double arrow Density space of space copper equals 8.1 space straight g divided by cc which space can space be space written space as space Mass over volume equals 8.1 space straight g divided by cc simillarly space Density space of space zinc equals 7.9 space straight g divided by cc and space volume space of space alloy equals 1.6 space cc Let space straight x space be space the space mass space of space copper space in space alloy hence comma space alloy space contains space the space substances space Volume space of space alloy equals Voume space of space copper plus Volume space of space zinc 1.6 equals fraction numerator straight x over denominator 8.9 end fraction plus fraction numerator 12.9 minus straight x over denominator 7.1 end fraction 1.6 equals 7.1 straight x plus 8.9 left parenthesis 12.9 minus straight x right parenthesis straight x equals 7.614 space straight g Mass space of space copper space is space 7.614 space straight g.    end style

Answered by Priyanka Kumbhar | 20th Oct, 2014, 09:57: AM

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