The transfer of heat by radiation is the transfer of heat from a hot object to another without any need for a material medium through which heat transfers, Heat is transferred from all resources of light by convection and radiation, while heat is transferred from the Sun by radiation only. The heat of the Sun is transferred to the Earth without any need for a material medium and this way is known as the transfer of heat by radiation, heat is transferred by radiation through material media & non-material ones, The heat is transferred from the heater to our bodies by convection & radiation. The electric heater is placed at the bottom of the room because when air (around the heater) is heated, its density decreases, so, it rises up to warm the room, while the cold air (with high density) falls down to be heated again and so on, The air conditioner is fixed at the upper part of the room to cool the air in the upper part of the room, where its density increases, so, it falls down, while the hot air rises up to be cooled and so on. Transfer of heat by convection is the transfer of heat in gases & liquids, where hot molecules which have less density rise upwards, while colder molecules which have more density fall down, The freezer of the fridge is found at the top of the fridge because when air is cooled, its density increases, so, it falls down to cool the food in the refrigerator, while the hot air (with low density) rises up to be cooled again and so on. Transfer of heat by conduction is the transfer of heat through some solid objects from the part with higher temperature to that with lower temperature, You feel hot when you touch a hot metallic spoon because heat is transferred from the hot object (spoon) to the cold object by conduction The transfer of heat by convection Heat transfers by conduction through some solid objects (metallic spoon) from one side to the other, Cooking pans are made up of copper & aluminium because they are good conductors of heat, When you put a metallic spoon in a cup of hot tea for a time, you feel the hotness of the spoon because heat is transferred through solids by conduction. The transfer of heat by radiation through material media and non-material ones (space).The transfer of heat by convection through gases and liquids.The transfer of heat by conduction through some solid objects.Heat is transferred from an object with a higher temperature to another of lower temperature, then it stops when they are equal in temperature, Heat is a form of energy which is transferred from an object with a higher temperature to that with a lower temperature, Temperature is the heat condition that determines the direction of heat energy whether from or to the object when it comes in contact with another. Ways of heat transfer How is heat energy transferred?

Linear energy transfer stopping power