Two 0.50 kg copper blocks are placed in an insulated container. One block is initially at 450 K and the other at 300 K. The specific heat capacity of copper is 390 J kg⁻¹ K⁻¹. Approximately how much energy is transferred as heat from the hotter block to the colder block by the time thermal equilibrium is reached?
a) 2.9×104J
b) 1.5×104J
c) 7.5×103J
d) 3.9×104J