THERMAL ENERGY

Chapter 5

I. TEMPERATURE, THERMAL ENERGY, AND HEAT – 5.1A. Temperature

1. Matter in motion2. Kinetic energy and temperature a. Please Define Temperature:

Measure of the average kinetic energy of allthe particles that make up an object.

B. Thermal Energy1. Please Define Thermal Energy:

Sum of the kinetic and potentialof the particles that make up an object.

2. Temperatures and thermal energy3. Mass and thermal energy

C. Heat1. Please Define Heat:

Energy that is transferred betweenobjects due to a temperature difference between those objects.

D. Specific Heat1. Please Define Specific Heat:

Amount of heat needed to raisethe temperature of 1 kg of a material

1oC.

2. Water as a coolant

3. Calculating thermal energy changes

E. Practice Problems p. 1421.

2.

3.

F. Measuring Specific Heat1. How does the Calorimeter measure

the specific heat of a substance?The scientists heats a sample of matter, measures the sample’s temperature change, its mass, and how much energy was transferred from the sample of matter to water inside the Calorimeter.

II. CONDUCTION, CONVECTION, AND RADIATION – 5.2A. Conduction

1. Please Define Conduction:Transfer of thermal energy by collisions

betweenthe particles that make up matter.

2. Collisions transfer thermal energy

3. Thermal conductorsa. Name three excellent

conductors: 1. Silver 2. Copper 3. Aluminum

B. Convection1. Please Define Convection:

Transfer of thermal energy in a fluidby the movement of warmer and cooler fluid from one place to another.

2. Convection currentsa. How does convection occur?

The rising of a heated fluid and

at the same time the falling of a cooling fluid.

3. Deserts and rainforests

C. Radiation1. Please Define Radiation:

The transfer of heat by electromagnetic

waves.

2. Radiation and matter3. Radiation in solids, liquids, and

gases

D. Controlling Heat1. Animals and heat

E. Thermal insulators1. Please Define Thermal Insulator:

A material through which thermalenergy moves slowly.

2. Insulated clothinga. Why is fleece a “good” insulator?

The fibers in the fleece trap theair and hold it next to you. Theair slows the transfer of your body’s thermal energy into its surroundings.Under the jacket, a blanket of warmair covers you.

3. Insulated buildingsa. Why is fiberglass a “good” insulator?

The fiberglass insulation containsfluffy material that contains pocketsof trapped air which slows the transferof heat to the surroundings.

4. Thermosesa. Why are Thermoses “good” insulators?

There is a vacuum between the twosurfaces of a thermos bottle. Thisminimizes the transfer of thermal energy by conduction and convection.Thermos bottles also have reflectivesurfaces, which minimize energy

transfersby radiation.

III. USING THERMAL ENERGY – 5.3A. Heating Systems

1. Forced-air systems

2. Radiator systems

3. Electrical heating systems

4. Solar heatinga. Passive solar heating

1. How do Passive solar heating systems work? In passive solar heating systems, materials inside a building absorb radiant energy

from the Sun and heat up during the day. At

night when the building begins to cool, thermal energy absorbed by these materials helps keep the room warm.

b. Active solar heating1. What is a solar collector?

Device used in an active solarheating system that

transformsradiant energy from the Suninto thermal energy.

B. Thermodynamics1. Please Define Thermodynamics: Study of the relationship between thermal

energy, heat, and work.

2. Heat and work increase thermal energy

3. The first law of thermodynamicsa. Please Define the First Law of

Thermodynamics:States that if the mechanical energy of a

systemis constant, the increase in the thermal energyof the system equals the sum of the thermalenergy transferred into the system and the

workdone on the system.

4. Isolated and non-isolated systems

5. The second law of thermodynamics a. Please Define the Second Law of Thermodynamics:

States that energy spontaneously spreads from regionsof higher concentration to regions of lower

concentration.

C. Converting Thermal Energy into Mechanical Energy1. Heat engines

a. Please Define Heat Engine:Device that converts some thermal energyinto mechanical energy.

2. Internal combustion enginea. Please Define Internal Combustion

Engine:Heat engine that burns fuel inside theengine in chambers or cylinders.

D. Doing Work to Transfer Thermal Energy1. Refrigerators

D. Doing Work to Transfer Thermal Energy2. Air conditioners

D. Doing Work to Transfer Thermal Energy3. Heat pumps

D. Doing Work to Transfer Thermal Energy4. Energy transformations and thermal energy a. Friction converts mechanical energy

into thermal energy when electricalgenerators rotate.

D. Doing Work to Transfer Thermal Energy4. Energy transformations and thermal energy b. A laptop computer converts electrical

energy into thermal energy.

IV. CHAPTER 5 REVIEWA. Please do Check Concepts 29-35 on page 164 in your Text.

B. Please do Standardized Test Practice 1-8 on page 166 in your Text.

C. I will type out a Pre-Test with an Equation sheet for you to practice

before your Test on Chapter 5.