Heat Transfer Methods

Study Notes

When an object is heated, energy is transferred to its thermal energy store, and as temperature increases, the process of heating can take place in three different ways depending on the medium involved.
In solids, heat is transferred by conduction, where vibrating particles transfer energy to neighboring particles, causing them to vibrate faster and collide more often, passing on the energy.
The process of conduction occurs mainly in solids because the particles are held together closely, allowing for more collisions and energy transfer.
Metals have a high thermal conductivity, transferring heat energy rapidly, whereas plastics have a low thermal conductivity, making them suitable as insulators.
Convection occurs mainly in fluids, where particles gain kinetic energy and move around faster by random diffusion, causing them to move away from the warmer region towards the cooler region.
As fluids heat up, they expand and become less dense, causing them to rise, and cooler fluids sink, creating a convection current.
Convection currents can be seen in real-life scenarios, such as oceans and buildings with radiators, and can be reduced by stopping the free flow of fluids.
Heat energy can also be transferred without particles through radiation, which involves the transfer of energy carried by infrared waves.
All objects constantly absorb and emit radiation, with hotter objects emitting more radiation, which is why it feels hot to put your hand over a barbecue even if you're not touching it.
The hotter the object is, the more radiation it emits, and this process is related to the electromagnetic spectrum.

Description

Learn about the three ways heat energy is transferred: conduction in solids, convection in fluids, and radiation through electromagnetic waves. Understand the mechanisms behind each process and their applications in real-life scenarios.