Question

(a) If two objects of different temperatures are placed in contact, will heat naturally flow from the object with higher internal energy to the object with lower internal energy? (b) Is it possible for heat to flow even if the internal energies of the two objects are the same? Explain.

Short answer

a) No, the heat will not naturally flow from the object with higher internal energy to the object with lower internal energy as they may have the same temperature.

(b) Yes, heat can flow even if the internal energies of the two objects are the same as they may have temperature differences

Step-by-step solution

Understanding internal energy

The total energy of a system is known as its internal energy. It depends on both the temperature of the system and the number of molecules available in it.

Step 2:(a) Effect of the internal energy on heat flow when two objects have different temperatures

Internal energy refers to the total energy of all the molecules in an object. It depends on

1. the temperature of the object, and
2. the number of molecules in the object.

So, it may be possible for an object to have high internal energy at a lower temperature (due to a large number of molecules), compared to another object at a higher temperature. If both are placed in contact, heat will naturally flow from the body at a higher temperature to the body at a lower temperature, irrespective of their internal energies.

Thus, the heat will not naturally flow from the object with higher internal energy to the object with lower internal energy.

Step 3:(b) Evaluation of the heat flow when two objects have similar internal energies

It may be possible for two objects to have the same internal energy at different temperatures as it also depends on the number of molecules.

The internal energy is the same, but heat can still flow from the object having a higher temperature to the object having a lower temperature when placed in contact.

Of the two objects, one may be at a higher temperature withfewer molecules, and the other may be ata lower temperature with more molecules. In that case, it is possible for both objects to have the same internal temperatures, but the heat will still flow from the object ata higher temperature to the one at a lower temperature.

Thus, the heat can flow even if the internal energies of the two objects are the same as they may have temperature differences.