For a 2 kg substance with specific heat capacity c = 4184 J/(kg·K) that undergoes a temperature change ΔT = 5 K, how much heat Q is transferred?

For a 2 kg substance with specific heat capacity c = 4184 J/(kg·K) that undergoes a temperature change ΔT = 5 K, how much heat Q is transferred?

• A. 41840 J
• B. 20920 J
• C. 8368 J
• D. 10460 J

Answer: (A)

Heat transferred depends on how much mass changes temperature, how resistant that substance is to heating (its specific heat), and how much the temperature changes: Q = m c ΔT. Here mass is 2 kg, specific heat is 4184 J/(kg·K), and the temperature change is 5 K. Multiply step by step: m c = 2 × 4184 = 8368 J/K, then Q = 8368 × 5 = 41840 J. The Kelvin and Celsius scales give the same numerical ΔT, so the 5 K change directly scales the heat. The result is in joules, as expected. If the temperature change were smaller, or the mass or c were smaller, the heat would be proportionally smaller.

Heat transferred depends on how much mass changes temperature, how resistant that substance is to heating (its specific heat), and how much the temperature changes: Q = m c ΔT. Here mass is 2 kg, specific heat is 4184 J/(kg·K), and the temperature change is 5 K. Multiply step by step: m c = 2 × 4184 = 8368 J/K, then Q = 8368 × 5 = 41840 J. The Kelvin and Celsius scales give the same numerical ΔT, so the 5 K change directly scales the heat. The result is in joules, as expected. If the temperature change were smaller, or the mass or c were smaller, the heat would be proportionally smaller.