What is an example of a process that would satisfy the conse

What is an example of a process that would satisfy the conservation of energy principle but not actually be observed in nature?

Solution

Examples:

1. A cup of hot coffee left in a cooler room eventually cools off. The reverse of this process- coffee getting hotter as a result of heat transfer from a cooler room does not take place.

2.        Consider heating of a room by passage of electric current through an electric resistor. Transferring of heat from room will not cause electrical energy to be generated through the wire.

3.        Consider a paddle-wheel mechanism operated by fall of mass. Potential energy of mass decreases and internal energy of the fluid increases. Reverse process does not happen, although this would not violate first law.

4.        Water flows down hill where by potential energy is converted into K.E. Reverse of this process does not occur in nature.

Processes proceed in a certain direction and not in the reverse direction. The law of conservation of energy places no restriction on direction.

A process will not occur unless it satisfies both the first and second laws of thermodynamics.