Thermal Energy

Thermal Energy

• Thermal energy is the total energy of the particles in an object, depending on temperature and mass.
• An object at a high temperature has more thermal energy than at a lower temperature.
• Thermal energy is different from kinetic energy due to the motion of the object as a whole.

Thermal Energy and Heat

• Thermal energy is not the same as heat.
• Heat is the energy in transit between substances or systems due to a temperature difference between them.
• Heat always flows from warmer materials to cooler materials.

Heat Transfer

• Heat transfer is energy in transit due to a temperature difference.
• The basic requirement for heat transfer is the presence of a temperature difference.
• There can be no net heat transfer between two mediums at the same temperature.
• The rate of heat transfer depends on the temperature difference in a certain direction.
• The larger the temperature difference, the higher the rate of heat transfer.

Conduction

• Conduction is the transfer of energy as heat from one substance to another when they are in direct contact.
• Conduction occurs when objects at different temperatures come into contact with each other.
• Energy is transferred from the warmer object to the cooler object until their temperatures are equal.
• Conduction can also occur within a single object, transferring energy from the warmer part to the cooler part.

Convection

• Convection is heat transfer by material moving from one place to another.
• In most substances, as temperature increases, the density of the liquid or gas decreases.
• Thermal energy is transferred from hot places to cold places due to convection.
• Gravity is one of the major forces affecting fluid flow in convection.
• Density differences due to temperature changes cause fluid movement in the presence of gravity.