1. Heat and Temperature
Unit 4 Lesson 2

2. Quick lab: Kinetic and Thermal Energy
Materials:
2 beakers, labeled A and B
2 thermometers
1 food coloring
Hot water (~300 ml)
Cold water (~300 ml)
1 timer
Procedures
Fill beaker A with hot water. Fill beaker B with cold water. Record the temperature at 0 minutes.
Drop in ONE drop of food coloring in each beaker at almost the same time. START the timer and DRAW what you observe happening to the food coloring in the beakers. DO NOT STIR the water and do not touch the thermometer.
Watch the timer and RECORD the temperature at 1 minutes and at 2 minutes, DRAW the food coloring, and WRITE what you observe happening.
Do not allow the beakers to touch or be near each other or they will transfer heat to one another.

3. Cold water
Hot water

4. How are energy & temperature related?
All matter is made of moving particles and has kinetic energy.
Temperature is a measure of the average kinetic energy of particles.
Thermal energy is a measure of the total kinetic energy of ALL particles.
The faster a particle moves, the more kinetic energy it has.

5. What is heat?
Heat is the energy that is transferred between objects that are at different temperatures.
Objects in contact will transfer energy until temperatures are equal in both objects.
Energy flows from higher to lower temperatures

6. How does kinetic energy change as particle motion increases and decreases?

8. Temperature
Temperature is a measure of the average kinetic energy of particles.
To measure temperature, we use a thermometer.
Thermometers can come in different styles, from a liquid based thermometer to an electric thermometer.

9. How does a liquid thermometer work?
It’s simple: thermal expansion!
When the liquid gets hot, as most substances do, the molecules move further apart. This causes the substance to expand.

10. What is the difference between Celcius ANDFarenheit?

11. What is kelvin?

12. Let’s practice 98 -273 -30 Fahrenheit Celsius Kelvin Body Temperature
Room Temperature
Water Freezes
Water boils
Absolute Zero
-273
Average temperature of North Pole
-30
Average temperature of Coconut Creek in July
Average temperature of dry ice
Average temperature of Mars

13. What is thermal expansion?
As space between particles increases, a substance expands.
The increase in volume that results from an increase in temperature is called thermal expansion.
Thermal expansion causes a change in the density of a substance.

14. Thermal Energy
Thermal energy is the total kinetic energy of particles.
Thermal energy depends on the number of particles.
More particles (BIGGER OBJECT) means more thermal energy.

15. VS.

16. Now YOU try it!
Cut a picture of an object from a magazine. Glue the picture onto an index card.
Copy the following table into your notes.
Find three people around the room and record what object they have in your table. Then determine which object has a higher temperature and which object has a higher thermal energy.
My Object
Object #2
Higher Temperature?
Higher Thermal Energy?

17. My Object
Object #2
Higher Temperature?
Higher Thermal Energy?

18. Quick Lab What are the three ways heat transfers?
Convection, Conduction, and Radiation
Directions:
Fill one beaker with 150 ml of water. You can leave the thermometer in the beaker.
Place the beaker of water on the hot plate. Turn on the hot plate to HIGH.
Allow the water to boil. Turn off the hot plate one the water boils.
Drop one drop of food coloring into the water once you have turned off the hot plate. Observe the convection currents that are occurring in the water.

21. Radiation
Radiation is the transfer of energy as electromagnetic waves.
The sun transfers energy to Earth by radiation.
Radiation can transfer energy to objects that are not in direct contact.

22. Where does radiation occur on Earth?
How does the sun heat Earth?

23. Conduction
Conduction is the transfer of energy from one object to another object through direct contact.
When objects touch, their particles interact.
The greater the energy difference, the faster the transfer of energy by conduction occurs.

24. Where does conduction happen on earth?
Any time two objects of different temperatures touch in the Earth system, energy is transferred from one object to another
The heat from the ground heats up the atmosphere at night causing wind
The lizard warms himself on a rock

25. convection
Convection is the transfer of energy due to the movement of matter.
Convection occurs because most matter becomes less dense when it gets warmer.
Convection currents form as warm and cool matter rise and fall due to temperature and density differences.

26. Where does convection occur on earth?
Energy moves through the atmosphere as warm air rises and cool air sinks.
Ocean water has different densities due to temperature and the amount of salt in the water.
Energy is transferred through rock material from Earth’s core to the surface by convection currents

27. Where does conduction occur on earth?
Energy can transfer by conduction from warm ground to cool air at Earth’s surface.
Warm air can transfer energy to cooler water and cause evaporation. If water vapor transfers energy to air, the water vapor can condense.
Energy can be transferred in rock by conduction, but very slowly.

28. Lets Picture it!

29. In closing…

30. Is this radiation, conduction, or convection?
An ice - cube in your hand

31. Is this radiation, conduction, or convection?
The A/C in your room

32. Is this radiation, conduction, or convection?
Sun rays warming a puddle

33. Is this radiation, conduction, or convection?
An egg in a hot skillet
This Photo by Unknown Author is licensed under CC BY

34. Is this radiation, conduction, or convection?
Using a blow dryer
This Photo by Unknown Author is licensed under CC BY-NC-ND

35. Is this radiation, conduction, or convection?
A lava lamp

36. Is this radiation, conduction, or convection?
Getting warm from the fireplace in winter
This Photo by Unknown Author is licensed under CC BY-SA

37. Is this radiation, conduction, or convection?
The spoon inside a cup of coffee gets hot at the end
This Photo by Unknown Author is licensed under CC BY-SA