Answer: 126,000 J.
- A 12,600 J
- B 126,000 J
- C 1,260 J
- D 1,260,000 J
Correct answer: B. 126,000 J
Explanation: Q = msΔT = 0.5 × 4200 × 60 = 126,000 J.
During a phase change (melting or boiling), temperature stays constant while heat is absorbed entirely as latent heat (Q=mL); temperature only rises again once the substance is fully in its new phase.
Concept context
Temperature scales, thermal expansion, calorimetry, and the three modes of heat transfer including radiation laws.