A 300 g copper calorimeter holds 500 g water at 20°C. A 500 g copper block at 100°C is dropped in. Final temperature is 25°C. Find the specific heat of copper (J kg⁻¹ K⁻¹).
Physics · Mixed Chapter
JEE Main Practice

Question

A 300 g copper calorimeter holds 500 g water at 20°C. A 500 g copper block at 100°C is dropped in. Final temperature is 25°C. Find the specific heat of copper (J kg⁻¹ K⁻¹).

G1 Physics · Accepted Answer

Step 1: Let specific heat of copper be c; take cwater ≈ 4200 J kg⁻¹ K⁻¹. Step 2: Heat lost by block = 0.5c(100−25) = 37.5c. Step 3: Heat gained by calorimeter and water = (0.3c + 0.5×4200)(25−20) = 1.5c + 10500. Step 4: Hence 37.5c = 1.5c + 10500 ⇒ c ≈ 291.7 J kg⁻¹ K⁻¹, approximately 290 in the printed key.