200 g of hot water at 80∘C is added to 300 g of cold water at 10∘C.Neglecting the heat taken by the container,calculate the final temperature of the mixture of water.Specific heat capacity of water =4200 J kg−1 K−1 .
Let the final temperature be ToC.
So, heat lost by hot water = Heat gained by cold water
⇒0.2×4200×(80−T)=0.3×4200×(T−10)
⇒16−0.2T=0.3T−3
⇒0.5T=19
∴T=38oC