Question

question 14 of 30 how is heat transferred when a person holds a pen that is already at body temperature? a. from the pen to the hand b. in both directions between the pen and the hand c. from the hand to the pen d. heat is not transferred.

Explanation:

Heat transfer occurs due to a temperature difference. When two objects are at the same temperature (the pen and the hand here, as the pen is at body temperature), there is no net heat transfer. However, thermal energy (heat) is still exchanged between them in both directions, but the rates are equal, so there's no net transfer. Wait, no—wait, the key is: heat transfer is the net movement of thermal energy from a higher - temperature object to a lower - temperature object. If the pen and the hand are at the same temperature (body temperature), the thermal energy is transferred in both directions between them (from pen to hand and hand to pen) at the same rate. So the net heat transfer is zero, but heat is transferred in both directions.
Wait, let's recall the concept of heat transfer. Heat transfer by conduction (in this case, since the person is holding the pen, conduction is the mode) happens when there is a temperature gradient. But when the temperatures are equal, the rate of heat transfer from the pen to the hand is equal to the rate from the hand to the pen. So heat is transferred in both directions between the pen and the hand.

Answer:

B. In both directions between the pen and the hand