How can thermal equilibrium be experimentally verified?

Thermal equilibrium can be experimentally verified by observing no net flow of heat between two objects in contact.

To understand this in more detail, let's first define what thermal equilibrium is. In physics, thermal equilibrium is a state in which all parts of a system are at the same temperature. This means that there is no net flow of thermal energy between any two parts of the system. When two objects are in thermal contact and no heat flows between them, they are said to be in thermal equilibrium.

To experimentally verify thermal equilibrium, you would need two objects at different temperatures. Place these objects in contact with each other and observe the flow of heat. Initially, the heat will flow from the hotter object to the cooler one. This is because heat always flows from a region of higher temperature to a region of lower temperature, in an attempt to equalise the temperatures.

As time passes, you will notice that the rate of heat flow decreases. Eventually, the flow of heat will stop completely. At this point, the temperatures of the two objects are equal. This is the point of thermal equilibrium.

To confirm this, you can use a thermometer to measure the temperatures of the two objects. If the temperatures are the same, then the objects are indeed in thermal equilibrium.

Remember, this experiment assumes that no heat is lost to the surroundings. In a real-world scenario, you would need to conduct this experiment in a thermally insulated environment to prevent heat loss.

In summary, thermal equilibrium can be experimentally verified by observing that there is no net flow of heat between two objects in contact, and this is usually confirmed by measuring the temperatures of the objects and finding them to be equal.