How does heat transfer occur?
Generally speaking, when a medium “is hot” and comes into contact with another medium (with a lower temperature), it causes the latter to also heat up. After a few seconds or minutes, both media will achieve thermal equilibrium, which is when both have the same temperature.
This process is imminent. The transfer of heat cannot be stopped, it can only be slowed down by intervening.
Types of heat transfer
In heat transfer, three forms of transfer can be identified: by conduction, by convection and by radiation .
- Conduction : heat is transmitted only if the particles of both bodies come into direct contact.
- Convection : it is similar to the previous one, only that the body (gas or liquid) transfers its heat through movement. The longer it moves, the more heat it loses, all this according to Newton’s Law of Cooling .
- Radiation : it occurs in a vacuum, without the need for bodies to come into contact. Just as it happens with the rays of the sun and the Earth.
The units that represent the carry-over going out are Kilocalories (Kcal) and British Thermal Unit (BTU)
Examples of heat transfer
- Melted ice on a hot surface.
- Forks or teaspoons that become hot when they come into contact with very hot food.
- The stove that heats the pots.
- The hot broth served, to which other ingredients are added and when in contact with the liquid, begin to heat up.
- The contact between two copper ends of a live wire.
- The heat generated by the motors, which heats the parts that are connected to it.
- The passage of electricity from an electrical appliance to the human body.
- The transfer of energy in any equipment that needs current to function.
- Hot air from hot air balloons.
- A hair dryer.
- Light the fire by rubbing.
- The effects of water vapor.
- The sun’s rays that heat the ground.
- A campfire, which raises the temperature of the immediate space a bit.
- The process inside a microwave.
- Roast a chicken in the oven.
- The light emitted by any light bulb.
- The heat of a radiator.
- Laser beam equipment.
- Gamma rays that are emitted from a nucleus.