Question 21
Quantity of HeatHot water is added to three times its mass of water at 10°C and the resulting temperature is 20°C. What is the initial temperature of the hot water?
- A.100°C
- B.80°C
- C.50°C
- D.40°C
Show the answer and explanation
Answer: C (50°C)
Explanation
Heat lost = heat gained: m(θ − 20) = 3m(20 − 10), so θ − 20 = 30 and θ = 50°C.