Question

Consider a hot baked potato. Will the potato cool faster or slower when we blow the warm air coming from our lungs on it instead of letting it cool naturally in the cooler air in the room? Explain.

Short answer

Answer: Blowing warm air from our lungs onto a hot baked potato slows down its cooling process compared to letting it cool naturally in the cooler air in the room. This is because the temperature difference between the potato and the warm air is less than that between the potato and the cooler room air, resulting in a slower rate of heat transfer by convection.

Step-by-step solution

In this case, the heat transfer occurs when the temperature of the hot baked potato is higher than the air temperature around it. The heat energy from the potato will transfer to the cooler air in the room, making the potato cool down gradually. This is a process called convection. #Step 2: Analyze the effect of blowing warm air on the potato#

When we blow warm air from our lungs onto the potato, we are essentially placing the potato in a temporary environment where the air temperature is higher than that of the room air. Therefore, the temperature difference between the potato and the air blown from our lungs will be less than that between the potato and the room air. #Step 3: Compare heat transfer rates#

Heat transfer by convection is directly proportional to the temperature difference between the hot object (in this case, the potato) and the surrounding air. When the surrounding air temperature is closer to that of the hot object (as it is when we blow warm air on it), the rate of heat transfer will be slower compared to when the surrounding air temperature is cooler in the room. #Step 4: Explain the observed effect on cooling rate#

Since the rate of heat transfer is slower when we blow warm air on the potato, it can be concluded that the potato will cool slower when we blow warm air on it as compared to letting it cool naturally in the cooler air in the room.