(4%) problem 17: the core of the sun has a temperature of 1.5 × 107 k, while the surface of the sun has a temperature of 4670 k (which varies over the surface, with the sunspots being cooler). treat the core of the sun and the surface of the sun as two large reservoirs connected by the solar interior. nuclear fusion processes in the core produce 3.8 × 1026 j every second. assume that 100% of this energy is transferred from the core to the surface. dho32@student. mtsac. edu