Which phenomenon involves heat transfer between stationary bodies in direct contact?

The phenomenon that involves heat transfer between stationary bodies in direct contact is conduction. This process occurs when two materials at different temperatures touch each other, allowing thermal energy to flow from the hotter material to the cooler one until thermal equilibrium is reached. During conduction, the heat transfer is facilitated by the collisions of particles within the material, which directly interact without any movement of the material as a whole.

For instance, if you place a hot metal rod in contact with a cooler piece of metal, the atoms in the hotter rod vibrate more vigorously and collide with the atoms in the cooler rod, transferring energy and increasing the temperature of the cooler metal. This makes conduction a critical mechanism in many practical applications, such as cooking, heating systems, and thermal insulation design.

The other choices represent different heat transfer mechanisms: convection involves the movement of fluids, radiation refers to heat transfer through electromagnetic waves without the need for a medium, and evaporation is a phase change process rather than a heat transfer method between stationary bodies. Understanding conduction and its characteristics is essential for analyzing thermal systems effectively in power engineering contexts.