A thermally insulated, closed copper vessel contains water at `15^@C`. When the vessel is shaken vigorously for 15 minuts, the temperature rises to `17^@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(J)/(kg-K)` and `4200(J)/(kg-K)` resprectively. Neglect any thermal expansion.
(a) How much heat is transferred to the liquid vessel system?
(b) How much work has been doen on this system?
(c ) How much is the increase in internal energy of the system?

Answer

(a) zero (b) `1764 J` (c ) `1764 J`

Explanation

(a), Zero because there is no heat transfter form outside.
(b) `W = 100 xx 10^(-3) xx 420 xx2xx 200 xx10^(-3) xx4200 xx2 = 1764 J`.
(c ) `DeltaU = 1764 J`