InterviewSolution
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InterviewSolution
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A thermally insulaated, closed copper vessel contains water at `15^(0)C`. When the vessel is shaken vigorously for 15 minutes, the tempreture rises to `17^(0)C`. The mass of the vessel is 100 g and that of the water is 200 g. the specific heat capacities of copper and water are `420 Jkg^(-1) K^(-1)` and `4200 J kg^(-1)K^(-1)` respectively. negalect any thermal expansion. (a) how much heat is transferred to the liquid-vessel system ? (b)how much work has been done on this system? (c ) how much is the increase in internal energy if the system ? |
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Answer» Correct Answer - A::B::C::D `t_1=15^@C,t_2=17^@C,` `Deltat-t_2-t_1` `=`17^@C-15^@C=2^@C=275 K` `m_v=100g=0*1kg.,` `m_w=200g=0*2kg` ` Sp.heat capacity of` `c_u=420 J/kg-k` `Sp.heat capacity of water `=4200 J /kg-k (a) The heat transferred to the liquid vessel system is 0. The internal heat is shared in between the vessel and water. (b) Work done on the system = Heat product unit ` `rArr bw=100x10^-3x420x2+200` `x10^--3x4200x2` `=84+84x20=84x21` `=1764 J` ` (c)`dQ=0,dU=-dW=1764` ` since `dw =-ve work done in the system |
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