What condition allows heat to flow quicker between two objects?

The condition that allows heat to flow quicker between two objects is a greater temperature difference. This principle is rooted in the laws of thermodynamics, specifically the second law, which states that heat naturally flows from areas of higher temperature to areas of lower temperature. When there is a significant temperature difference, the driving force for heat transfer increases, leading to a more rapid exchange of thermal energy between the two objects.

This occurs because the greater the disparity in temperature, the stronger the tendency for heat to flow from the hot object to the colder one until thermal equilibrium is reached. For example, if you place a hot cup of coffee next to an ice-cold glass of water, the heat will transfer rapidly from the coffee to the ice water due to their substantial temperature difference, causing the coffee to cool down and the ice to melt more quickly.

In contrast, other conditions, such as material density or size difference, do not directly influence the rate of heat flow as significantly as the temperature difference. A greater distance between objects can even retard heat transfer, as the energy has to travel through the intervening space, which may introduce further resistance to the flow of heat. Thus, the temperature difference is the key factor in the speed of heat transfer between two bodies.