Three identical copper blocks have the following initial temperatures:
• Block A: 400 K
• Block B: 300 K
• Block C: 350 K
Step 1: Block A is placed in thermal contact with Block C until they reach thermal equilibrium and are then separated.
Step 2: Block C (now at the new temperature) is placed in thermal contact with Block B until they reach thermal equilibrium.
After both steps are complete, which block(s) have experienced a net gain of thermal energy compared with their initial states?
(a) Blocks B and C
(b) Block C only
(c) Block B only
(d) Blocks A and C