Heat in the CH 15 Prentice Hall p.509-514 CH 15 Prentice Hall p.509-514 At 16 16. 2 ppt Atmosphere.

Heat in theHeat in theCH 15 Prentice Hall

p.509-514CH 15 Prentice Hall

p.509-514

At16

16. 2 ppt

AtmosphereAtmosphere

• Problem:– What will happen when the egg

is placed on the bottle once the paper is lit?

• Hypothesis:• Observations:

Egg Demonstration

• Observations: • Identify:

– Where the pressure was low and high.

– What was the wall?

Egg Demonstration

• Problem:– What will happen to the

heated can when the opening is sealed with water.

• Hypothesis:– The can will….

• Observations:

Soda Can

• Problem: How will placing a drinking glass over lit candles sitting in a pie pan filled with water affect the water in the pan?

• Hypothesis (one for each picture)

1,2,3 Candle

1,2,3 Candle Diagram

1,2,3 Candle Diagram

• Explain what happened?– Where was the

pressure high and low?

– What was the wall in this situation?

– Why was the pressure low?

Heat TransferHeat TransferChapter 16 Section 2

Pages 532-535Chapter 16 Section 2

Pages 532-535

• Is the total energy of motion in the molecules of a substance. • Gases are made of molecules that are

constantly moving. The faster they are moving the more energy they have.

Fast

More Energy

Slow

Less Energy

Thermal Energy

• The average amount of energy of motion in the molecules of a substance.

• It is a measure of how hot or cold something is.

Temperature

More Energy

WarmerLess Energy

Cooler

• Thermometer- An instrument used to measure the temperature, consisting of a thin, glass tube with a bulb on one end that contains a liquid, usually mercury or alcohol.

– Liquids expand when heated or contract when cooled.

– It is measured in degrees Celsius or Fahrenheit.

• Freezing 0°C = 32°F• Boiling 100°C = 212°F

Measuring Temperature

Speed of Molecules & Temp

• What happens to the speed of the molecules when temperature is increased?

• What happens to the amount of times the walls are hit?

Temperature and Volume

• What happens to the volume of a gas when it is heated?

• Heating air molecules increases their energy making them move faster.

• As a result, they will hit the wall more often, moving the wall to the right.– Lowers the pressure on the warmer side– Increases pressure on the cooler side.

Air Molecule Model Situation 3

Faster

Molecules

Slower

Molecules

• Cooling air molecules decreases their energy making them move slower.

• As a result, they will hit the wall less often, moving the wall back to the left.– Pressure on the right side is higher, pushes back towards

the left side which has a lower pressure.

Air Molecule Model Situation 4

Faster

Molecules

Slower

Molecules

• The energy transferred from a hotter object to a cooler one.

• Three ways it is transferred.– Radiation– Conduction– Convection

Heat

• The direct transfer of energy over long distances of empty space.

• Moves in waves. (Electromagnetic Waves)

• No direct contact • Can not see it, but feel it a heat

(Infrared)– Sunlight– Open fire

ClimateRadiation

• Heat transfer by direct contact of particles of matter. (Transfer by Touching)

• Particles bump into each other and transfer their energy heating them up.– Putting your hand on a hot

stove.

Conduction

• Heat transfer by the circular movement of a fluid (liquids and gasses).

• Particles flow transferring heat energy.• Caused by differences in density.

Convection

• Density: the amount of mass in a given volume. D=M/V

• Heated Fluids:– Move faster and bump into other particles.– They spread out increasing the volume.– Density decreases

• Cooling Fluids– Move slower– They come together decreasing the volume.– Density increases

How Convection Works

Heat Transfer in the Troposphere

• Radiation, conduction and convection work together to heat the troposphere.

• The surface absorbs solar energy.

• Air near the surface is warmed by radiation and conduction of heat from the surface to the air.

Heat Transfer in the Troposphere

• Convection causes most of the heating of the troposphere.

• Convection Current-– Heated molecules have more energy.– They move faster and spread further apart.– Air becomes less dense and rises.– Cooler air is more dense and sinks.– Moves into the place of the rising air.

Heat Transfer in the Troposphere

1,2,3 Candle Diagram

• Diagram Explanation:

• Written Explanation:

Egg Demonstration

• Diagram Explanation:

• Written Explanation:

Can Demonstration