HEAT

HEATIt is the movement of

Thermal Energy from a substance at a higher temperature to another at a lower temperature.

Matter contains thermal Energy……only when this thermal energy is transferred it is called heat.

HEATWhen you touch a

hot stove, energy enters your hand from the stove because the stove is warmer than your hand.

HEATIf you touch ice,

energy transfers from your hand into the cold ice.

HEAT Energy transfer is always from a warmer to

a cooler substance. Heat is transferred by Conduction,

convection, and Radiation

Conduction: heat is transferred through solids by conductionExample: A metal spoon being

heated in a pot of water being heated on the electric stove. The fast moving particles of the electric coil collide with the slow moving particles of the cool pot. Heat is transferred, making the slow particles move faster.

Then the particles of the pot collide with the particles of water which then collide with the particles of the spoon and the metal spoon becomes hotter.

Conductors: A material that allows heat to move through it easilyGood ConductorsMetals:CopperGoldSilverIronAluminumSteel

Poor Conductors (Insulators): These do not conduct heat easily

WoodwoolPaperWaxAirExample: Insulations in

the wall of homes, clothes, blankets, fiberglass

Convection: Transfer of heat in gases and liquidsWhen gases and liquids

are heated the particles move faster and farther apart and as a result becomes less dense than the cooler surrounding gas or liquid.

The less dense gas or liquid rises and the cooler, denser gas or liquid moves to take its place.

Convection: Transfer of heat in gases and liquidsConvection is the

movement that transfers heat within the water.

When water at the bottom is heated, its particles move faster and farther apart. As a result the water becomes less dense and moves on top of the more dense water.

Convection currentsThis flow of water creates

a circular motion called convection currents.

Examples: Convection currents are used to transfer heat throughout a building, baseboard heaters

Environment: The air heated by the sun is transferred throughout earth atmosphere by convection currents

Radiation: Transfer of Energy by electromagnetic rays.Examples: Feel the

heat near the stove or oven

Radiation from the lamp

Radiation from the sun

Radiation does not require matter to transfer thermal energy

Conductors and Insulators1.Tile and carpet at the

same temperature but the tile feels Cooler because……………..

Tile is a good conductor and …..it transfers heat away from skin faster than the rug which is an insulator which slows the transfer of heat.

Specific HeatThe amount of energy

required to raise the temperature of 1 kg of a substance by 1 Kelvin is called Specific Heat.

EX: Sand heats faster than water on a sunny day (At the same temperature)

Unit: Joules per Kilogram-Kelvin (J/Kg.K)

Materials with a high Specific heat can absorb a lot of heat without changing in temperature.

Test Yourself:What is Absolute

Zero?

What is Absolute Zero?Coldest

Temperature possible

-273 degrees Celsius

No more heat can be removed from it

What is Thermal Energy?

What is Thermal Energy?The total energy of all the particles in a

substanceThe more particles of a substance at given

temperature……..the more the thermal energy

What is Heat?

What is Heat?The movement of thermal energy from

warmer to cooler objectsHeat is transferred by:__C_______________________C______________________R___________________Radiation is the transfer of energy

through…………………………waves.

Heat transfers from:

Pick One option:

Cool to warm

Warm to cool

Many directions

What are Insulators?

What are Insulators?A material that does not conduct heat well

What is Specific Heat?Give examples of objects with Low and high

Specific heat

What is Thermal Expansion?

What is Temperature?

Good Luck