Medium
How much heat is required to raise the temperature of 2 kg of water from 20 °C to 50 °C? (Specific heat capacity of water = 4200 J/kg °C)
Explanation
Explanation
Step 1: Formula: Q = m × c × ΔT.
Step 2: m = 2 kg, c = 4200 J/kg °C, ΔT = 50 − 20 = 30 °C.
Step 3: Q = 2 × 4200 × 30 = 8400 × 30 = 2,52,000 J.
Step 4: In kilojoules this is 252 kJ.
Answer: 2,52,000 J.
PRO TIP
Re-check your working by substituting the answer back into the original question.