Which method of heat transfer involves direct contact?

The method of heat transfer that involves direct contact is conduction. In conduction, heat is transferred through a material or between materials that are in direct physical contact with each other. This process occurs at the molecular level, where faster-moving molecules (those with more thermal energy) collide with slower-moving molecules, transferring some of their energy in the process.

For example, if you place a metal spoon in a hot cup of coffee, the heat from the coffee transfers directly to the spoon, warming it up. This transfer of heat continues until thermal equilibrium is reached, meaning the spoon and coffee reach the same temperature. This characteristic of conduction makes it an essential process in many everyday applications, such as cooking and heating.

Convection, on the other hand, involves the movement of fluids (liquids or gases) and does not require direct contact, while radiation is the transfer of energy through electromagnetic waves and also does not require a medium. Evaporation is a phase change that absorbs heat but does not involve conduction in the traditional sense.