Which statement describes both solar heating and radiative cooling correctly?

• A. Ground heats slower; Water cools slower
• B. Ground heats faster; Water cools faster
• C. Ground heats faster; Water cools slower
• D. Ground heats slower; Water cools faster

Answer: (D)

The key idea here is how quickly a surface responds to heat input and how quickly it loses that heat, which depends on thermal mass (heat capacity) and the ways heat can escape (radiation, convection, and for water, evaporation).

Ground generally has less ability to store heat per unit area compared with water and often exchanges heat with the surrounding air and deeper layers less aggressively. That means, under solar input, its surface temperature rises more slowly, so it heats slower. When heat starts to leave the surface, water has a strong mechanism to shed energy quickly: evaporation takes away a lot of energy as latent heat, and its surface can also radiate efficiently. As a result, the same surface can cool faster once cooling begins. Taken together, describing ground heating slowly and water cooling quickly aligns with how these surfaces typically respond to solar heating and radiative cooling in many environments.