Question Number 137641 by mey3nipaba last updated on 04/Apr/21
Answered by mr W last updated on 05/Apr/21
Commented by mey3nipaba last updated on 05/Apr/21
$${oh}\:{okay}.\:{i}'{m}\:{sorry}.\:{thanks}\:{though}\:{for}\:{the}\:{solution}. \\ $$
Commented by mr W last updated on 05/Apr/21
$${wood}\:{alone}\:{in}\:{liquid}: \\ $$$$\rho_{{W}} {V}_{{W}} =\rho_{{L}} {V}_{{L}} \\ $$$$\rho_{{W}} =\frac{{V}_{{L}} }{{V}_{{W}} }\rho_{{L}} =\frac{\mathrm{75}}{\mathrm{100}}×\mathrm{1}.\mathrm{2}=\mathrm{0}.\mathrm{9} \\ $$$${wood}\:{with}\:{glas}\:{in}\:{liquid}: \\ $$$$\rho_{{G}} {V}_{{G}} +\rho_{{W}} {V}_{{W}} =\rho_{{L}} \left({V}_{{G}} +{V}_{{W}} \right) \\ $$$$\left(\rho_{{G}} −\rho_{{L}} \right){V}_{{G}} =\left(\rho_{{L}} −\rho_{{W}} \right){V}_{{W}} \\ $$$${V}_{{G}} =\frac{\left(\rho_{{L}} −\rho_{{W}} \right){V}_{{W}} }{\rho_{{G}} −\rho_{{L}} }=\frac{\mathrm{1}.\mathrm{2}−\mathrm{0}.\mathrm{9}}{\mathrm{2}.\mathrm{4}−\mathrm{1}.\mathrm{2}}×\mathrm{100}=\mathrm{25}\:{cm}^{\mathrm{3}} \\ $$$${m}_{{G}} =\mathrm{1}×\rho_{{G}} {V}_{{G}} =\mathrm{1}×\mathrm{2}.\mathrm{4}×\mathrm{25}=\mathrm{60}\:{g} \\ $$