Suppose a plant is receiving 150 units of heat per minute due to solar radiation, and 45 units of heat per minute due to infrared radiation. Sixty units per minute of solar radiation are reflected back by the leaves, and the plant emits 30 units of infrared radiation. It also loses 50 units of heat per minute through evapotranspiration. The temperature of the plant is not changing. Based on this information, we can conclude that the combination of conduction and convection is resulting in a net _______of heat by the plant, and that its temperature is currently _______ than the ambient temperature.
A) gain; warmer
B) gain; colder
C) loss; warmer
D) loss; colder

Question

Quizplus · Accepted Answer

The plant is in thermal equilibrium, meaning the heat gained equals the heat lost. The net heat gain from radiation is 105 units (150 + 45 - 60 - 30), and it loses 50 units through evapotranspiration. Therefore, conduction and convection must account for a net loss of 55 units to balance the heat budget. Since the plant is losing heat, it must be warmer than the ambient temperature to drive this heat loss.

Suppose a Plant Is Receiving 150 Units of Heat Per