During a specific time interval, the temperature of a solid object is observed to remain constant. In this interval,

Step-by-step solution

During the time interval when the temperature of the solid object is constant, it is possible that the object is undergoing a phase change (such as melting or sublimation). During a phase change, heat can be supplied to or extracted from the object without any change in its temperature. Alternatively, the object might be in thermal equilibrium with its surroundings, meaning the rate at which heat is supplied to it equals the rate at which heat is extracted from it. Thus, heat may have been supplied to or extracted