A 0.50 kg block of aluminum and a 0.20 kg block of copper both start at 25 °C. Each block individually absorbs 1.50 kJ of energy. Immediately afterward the two blocks are placed in thermal contact inside an insulated container and allowed to reach a common final temperature with no energy lost to the surroundings. Given the specific heats
• Aluminum: 900 J kg⁻¹ °C⁻¹
• Copper: 390 J kg⁻¹ °C⁻¹
Which of the following is the best estimate of the final equilibrium temperature of the two-block system?
a) 42°C
b) 31°C
c) 29°C
d) 37°C