🔍 Key Concepts

• Difference between heat source and heat sink • How temperature difference (ΔT) affects the rate of heat transfer (think conduction, convection, radiation) • The basic definition of radiation compared with convection (mass motion of a fluid)

💭 Think About

• Which option correctly describes what a heat sink does: does it supply heat, or absorb/remove it? • In basic heat transfer formulas, what variable most strongly drives the rate of heat transfer: size of the object, or the temperature difference between hot and cold regions? • Does radiation require a fluid (like air or water) to move, or can it occur through empty space (like sunlight reaching Earth)?

✅ Before You Answer

• Be sure the heat sink is correctly described as the part that absorbs heat, not the hotter region that gives it off. • Recall that for heat transfer, a larger temperature difference (ΔT) generally means a higher rate of heat flow, all else equal. • Verify that radiation is not the same as convection; convection is tied to mass motion of a fluid, while radiation is not.