JEE Main 2019 Physics question
An unknown metal of mass 192 g heated to a temperature of 100°C was immersed into a brass calorimeter of mass 128 g containing 240 g of water at a temperature of 8.4°C. Calculate the specific heat of the unknown metal if water temperature stabilizes at 21.5ºC. (Specific heat of brass is 394 J kg K)
Answer: (D)
Solution
0.192 s (78.5) = (0.24 × 4200 + 0.128 × 394)(13.1) ⇒ s ≈ 916–920 J kg K.