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Heat.

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Presentation on theme: "Heat."— Presentation transcript:

1 Heat

2 Temperature Scales 00C or 320F 1000C 2120F 00C 320F
The lower fixed point is the ice point, the temperature at which ice and water coexist at 1 atm of pressure: 00C or 320F The upper fixed point is the steam point, the temperature at which steam and water coexist at 1 atm of pressure: 1000C or F

3 Kinetic-Molecular Theory
What is Kinetic-Molecular Theory? This new theory stated that all matter is made up of atoms/molecules in constant motion. The faster they move, the hotter an object will be.

4 Internal Energy What Is Internal Energy?
Internal energy (also called thermal energy) is the energy an object or substance has due to the kinetic and potential energies associated with the random motions of all the particles that make it up.

5 Internal Energy The hotter something is, the faster its molecules are moving or vibrating, and the higher its temperature.

6 Internal Energy vs. Heat
The term heat refers is the energy that is transferred from one body or location due to a difference in temperature. Heat is internal energy when it is transferred between bodies.

7 Temperature equilibrium
Heat is defined as the transfer of thermal energy that is due to a difference in temperature. Two objects are in thermal equilibrium if and only if they have the same temperature.

8 Temperature equilibrium
Room temperature is at 30º C Coffee initial temperature is at 70º C Soda can initial temperature is at 5º C As long as there is a temperature difference between the system and the surroundings, there is a heat flow between them.

9 Heat Defined as Energy Heat is not something an object has, but rather energy that it absorbs or gives up. The heat lost by the hot coals is equal to that gained by the water. Hot coals Cool water Thermal Equilibrium

10 Heat Transfer by Conduction
Conduction is the process by which heat energy is transferred by adjacent molecular collisions inside a material. The medium itself does not move. Conduction Direction From hot to cold.

11 Heat Transfer by Convection
Convection is the process by which heat energy is transferred by the actual mass motion of a heated fluid. Heated fluid rises and is then replaced by cooler fluid, producing convection currents. Convection Convection is significantly affected by geometry of heated surfaces. (wall, ceiling, floor)

12 Heat Transfer by Radiation
Radiation is the process by which heat energy is transferred by electromagnetic waves. Radiation Sun Atomic No medium is required !

13 Heat transfer

14 To be cont……. Complete worksheet


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