Thermal Energy

What is Thermal Energy?

• a measure of the average value of the kinetic energy of the molecules in random motion. (SI unit for temperature is Kelvin {K})

• almost all substances expand when they are heated and contract when they are cooled; water is an exception

• sum of the kinetic and potential energy of all the particles in an object; thermal energy of an object increases as temperature increases

The First Law of Thermodynamics states that The increase in thermal energy of a system equals the work done on the

system plus the heat transferred to the system.

• True

• False

The Secound Law of Thermodynamics states that The increase in thermal energy of a system equals the work done on the system plus the heat transferred to the system.

• True

• False

The 2nd Law of thermodynamics states:

• It is impossible for heat to flow from cool object to warm object unless work is done.

• The increase in thermal energy of a system equals the work done on the system plus the heat transferred to the system.

• The transfer of energy by radiation is most important gases.

• None of the above.

Conduction:

• Transfer of thermal energy by collisions between particles in matter. (Occurs in solids, liquids, and gases.)

• Transfer of thermal energy in a fluid by the movement of warmer and cooler fluids from place to place. (Occurs in fluids. Rising of warmer fluid and sinking of cooler fluid forms a convection current)

• Transfer of energy by electromagnetic waves.( The transfer of energy by radiation is most important gases.)

Convection:

• Transfer of thermal energy by collisions between particles in matter. (Occurs in solids, liquids, and gases.)

• Transfer of thermal energy in a fluid by the movement of warmer and cooler fluids from place to place. (Occurs in fluids. Rising of warmer fluid and sinking of cooler fluid forms a convection current)

• Transfer of energy by electromagnetic waves.( The transfer of energy by radiation is most important gases.)

Radiation:

• Transfer of thermal energy by collisions between particles in matter. (Occurs in solids, liquids, and gases.)

• Transfer of thermal energy in a fluid by the movement of warmer and cooler fluids from place to place. (Occurs in fluids. Rising of warmer fluid and sinking of cooler fluid forms a convection current)

• Transfer of energy by electromagnetic waves.( The transfer of energy by radiation is most important gases.)

What is the difference between Temperature and Thermal Energy?

• Temperature is: A measure of the average value of the kinetic energy of the molecules in random motion. while

  Thermal energy is: the sum of the kinetic energy and potential energy of all the particles in an object.

• Temperature is: the sum of the kinetic energy and potential energy of all the particles in an object. while

  Thermal energy is: A measure of the average value of the kinetic energy of the molecules in random motion.

What is Heat ?

• This is the amount of heat needed to raise the temp of 1kg of some material by 1*C

• Q=mcΔT

• Thermal energy that flows from something at a higher temperature to something at a lower temp.

What is Specific Heat ?

• This is the amount of heat needed to raise the temp of 1kg of some material by 1*C

• Q=mcΔT

• Thermal energy that flows from something at a higher temperature to something at a lower temp.