THERMAL ENERGY II

Temperature is a measure of the average amount of kinetic energy possessed by the particles in a sample of matter. The more the particles vibrate, translate, and rotate, the greater the temperature of the object. You have hopefully adopted an understanding of heat as a flow of energy from a higher-temperature object to a lower-temperature object. It is the temperature difference between the two neighboring objects that causes this heat transfer. Heat is transferred from the hot water to the cold water until both samples have the same temperature.

Conductive heat flow involves the transfer of heat from one location to another in the absence of any material flow. The mechanism in which heat is transferred from one object to another object through particle collisions is known as conduction.

   Applications

• cooling a glass in an ice bucket
•   burning your hand on a hot tripod
•  holding the handle of a pan

Convection is the process of heat transfer from one location to the next by the movement of fluids. The moving fluid carries energy with it. The fluid flows from a high-temperature location to a low-temperature location. The two examples are heating water in a pot and heating air in a room.

Application

•  boiling water
•    hot air balloon rising
•    warm water on the surface of a lake and cold water at the bottom of the lake
•  air conditioning cooling a room
•   cooking rice in water

Radiation is the transfer of heat using electromagnetic waves. The transfer of heat by radiation involves the carrying of energy from an origin to the space surrounding it. The energy is carried by electromagnetic waves and does not involve the movement or the interaction of matter.

Application

•             Sun’s light warming the Earth
•             feeling warm when you sit in sunlight
•             a pan above the stove burner
•             barbeque meat with charcoal

Radiation for heat to reach the meat, conduction to cook it inside