A 0.05kg gold block at 1500∘C is placed in 0.6kg water at 25∘C in a 0.1kg copper calorimeter at 25∘C. Find the final tem
0.05×134×(1500−T) = (0.6×4186+0.1×386)×(T−25). 10050−6.7T = (2511.6+38.6)×(T−25) = 2550.2T−63755. 10050+63755 = 2550.2T+6.7T. 73805 = 2556.9T⇒T≈28.87∘C≈28.9∘C. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 28.9°C. This satisfies dimensional consistency and physical conditions given, so option D is scientifically correct.
Ref: NCERT Class 11 Physics, Chapter 11: Thermal Properties – Calorimetry.