Meaning of thermal energy and heat flow
Heat can be used to do some work and can be transfered one form to another due to temperature difference.In kinetic energy temperature is the measure of the average kinetic energy of particles,since kinetic energy is the energy in motion.In liquid and gases molecules collide with one another at very high speed.
The average kinetic energy of molecules in an objects is the temperature of that object.The higher the average kinetic energy the faster the movement of molecules and the higher the temperature,for example a large pot of boiling water and a smaller pot of boiling water the larger pot has more kinetic energy than the smaller one.
Therefore thermal energy is also called heat energy.
Heat flow is the transfer of heat from hotter body to a cooler body as a result of temperature difference.Thus,based on the principle of the law conservation of energy ,which states that energy can neither be created nor destroyed but can be transfered from one form to another .Examples
1 Heat energy travel from the sun to reach the earth surface and the organisms in it
2 Heat energy flow from the fire to the kettle to make the water in it boils
3 Heat flow from the fire to the still iron which is felt by a person after some time
Therefore thermal energy can be transfered from objects three main processes namely
1 conduction ,convection,radiation