thermal energy moves from a to b by
Answers
There are three ways that heat energy can move:
Conduction.
Convection.
Radiation.
Conduction
When you first pour boiling water onto a Pot Noodle, the plastic container feels cool on the outside. Soon, the heat energy has worked its way through the plastic and the container starts to feel hot on the outside. Heat energy has travelled through the solid plastic container. This process is called conduction.
Convection
Hot air rises in cold air. Hot water rises in cold water. This way of moving energy is called convection. When hot air rises, colder air has to move in to replace it. When hot water rises in a cup, colder water sinks to replace it.
This movement of a liquid or gas is called a convection current.
Convection cannot happen in solids, as the atoms aren't able to move around.
Radiation
"How to toast bread!" When a piece of bread is put in a toaster the wires inside the toaster glow red hot on either side of the bread.
How does the heat energy get to the bread?
How does Heat Energy Move?
Is it by conduction?
No, the heat energy cannot conduct through the air to the bread because air is a very bad conductor.
Is it by convection?
No, hardly any of the heat energy could have travelled to the bread by convection, as the hot air particles would rise out of the toaster.
The heat energy must have reached the toast some other way. It travelled as radiated heat. This heat energy movement is sometimes called heat waves, but strictly speaking, it is infrared radiation.