Question

A piece of copper of mass 1 kg is dropped into 2 kg of water at 15°C. If the final temperature of the mixture is 40°C, calculate the intial temperature of copper.

Answer 1

Specific heat of copper = 390 J kg^-1K^-1

Let the initial temperature of copper be t.

Heat lost by copper = Heat gained by water

1 x 390 x (t - 40) = 2 x 4200 x (40 - 15)

or, t- 40 = `(2 xx 4200 xx 25)/390` = 538.46

or, t = 578.46°C