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Find the change in internal energy in joule, when 10 g of air is heated from 30^@ C to 40^@ C. |
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Answer» SOLUTION :`(C_V~~ 0.172 kcal// kgK,J= 4200J // kcal) ` massof air`m=10 g = 10 XX 10^(-3)kg ` CHANGEIN temperature` =( 40-30) ~~ 10 K`specific heat at a constant volume `C_V` `= 0.172 k.cal//kg -k , J= 4200 J/kcal ` When gases are heated at constant volume then heat energy supplied is useful to INCREASE internal energy. ` therefore ` Change in internal energy =` dU= dU= mC_vdT ` ` dU= 10 xx 10^(-3) xx 0.172 xx 10^3 xx 10` `= 17.2cal= 72.24J` |
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