Practice question

Given: A copper block of mass 0.5 kg at 100° C is dropped into 1 kg of water at 20° C . Find the final temperature. (Specific heat of copper = 386 J kg^{-1 K^{-1, water = 4186 J kg^{-1 K^{-1 ) These values define the system as per NCERT data. Formula: Heat lost by copper = Heat gained by water. This is standard NCERT relation. Substitution & Calculation: m_c s_c (100 - T) = m_w s_w (T - 20) . 0.5 × 386 × (100 - T) = 1 × 4186 × (T - 20) . 19300 - 193 T = 4186 T - 83720 . 19300 + 83720 = 4186 T + 193 T . 103020 = 4379 T Rightarrow T approx 23.53° C . Result: The computed value matches expected outcome and confirms correct choice as per NCERT.