# HEAT.

## Presentation on theme: "HEAT."— Presentation transcript:

HEAT

What is Temperature? Temperature is the average kinetic energy of the particles of an object. As temperature increases , kinetic energy of the particles increases.

How is temperature related to the movement of the particles?
The faster the particles of an object move, the higher the temperature of the object.

Which particles are moving faster, those in a cup of hot tea or iced tea?

What is thermal expansion ?
Thermal expansion is the increase in the volume of a substance due to an increase in temperature .

What is the official SI unit of temperature?
Kelvin

Temperature conversion formulas
Celsius to Fahrenheit: oF = (9/5 * oC) + 32 oC  0F Fahrenheit to Celsius: oC = (5/9) * (oF – 32) oF  0C Celsius to Kelvin: K = oC + 273 oC  K Kelvin to Celsius: oC = K – 273 K  oC

Fill the missing blanks using the previous
oF oC K Water boils 100o Body Temperature 37o Room Temperature 68o Water freezes 0o Absolute zero

What is absolute zero? The lowest temperature on Kelvin scale
(zero Kelvin) At this temperature particles stop moving.

What is heat? Heat is the transfer of energy between two objects that are at different temperatures. When two objects of different temperature come in contact, energy is always transferred from the higher temperature to the lower temperature.

What is thermal energy? Thermal energy is the total energy of the particles that make up a substance. It is measured in Joules. Which one has more thermal energy?

What is thermal equilibrium?
Energy is transferred from the higher temperature object t o the lower temperature object until both objects reach the same temperature.

What are conductors? Conductors are substances that conduct thermal energy.

What is an insulator? An insulator is a substance that does not conduct thermal energy .

How is heat transferred?

Heat and temperature change

Thermal conductivity The rate at which a substance conducts thermal energy.

Specific heat capacity
The amount of energy needed to change the temperature of one Kg of a substance by one degree Celsius.

Specific heat capacity of different materials:
Silver 234 Copper 387 Glass 837 Wood 176 Steam 2010 Ice 2090 Aluminum 899 Water 4184

Matter and heat States of matter
Three states of matter: solid , liquid and gas.

heat technology Heat engines A machine that uses heat to do work.
Heat engines burn fuel to produce thermal energy in a process called combustion. There are two types of heat engines: external combustion and internal combustion heat engines.

External combustion: fuel is burned outside the engine.
Internal combustion: fuel is burned inside the engine.

Cooling system Cooling systems are used to transfer thermal energy out a particular area so that is feels cooler. Question: Will leaving the refrigerator door open on a hot day help to cool the kitchen?