A cold object in contact with a hot one never spontaneously transfers energy by heat to the hot
object. Which law describes this phenomenon?
The zeroth law of thermodynamics
The third law of thermodynamics
The second law of thermodynamics
The first law of thermodynamics

The phenomenon you’re describing is a classic example of the second law of thermodynamics, which states that heat cannot spontaneously flow from a colder body to a hotter body. This means that energy transfer will always move towards equilibrium, where the temperatures will eventually equalize. It’s a fundamental principle that even explains why you should always wear a coat in winter—you want to keep the heat from escaping your warmer body to the cold surrounding air!

In practical terms, this principle helps us understand why refrigerators work. They take heat from inside (the cold area) and pump it outside (to the warmer environment) using work input. This energy transfer mechanism is what keeps our food fresh and cool, demonstrating the second law of thermodynamics at play in our everyday lives.