Chapter 5

Complete 44-47

Conduction

-Collisions transfer thermal energy

-More energetic particles collide with less energetic particles

- The rate at which conduction transfers thermal energy depends on the material

- Metals are good conductors

Convection

Homework: Read 5.3, define vocab

Book Review

- Liquids and gases

- More energetic particles move from one place to another

- Fluids decrease in density when heated

-If a fluid is heated from below, a convection current forms

-Lava Lamp

- Deserts and Rainforests page 146

Section 2 Review

Research how a convection oven works.

Complete the Lab on pages 160-161

What is the difference between conduction and convection?

Radiation

Homework: Test!

- Transfer of energy by electromagnetic waves, such as light and microwaves

- Materials absorb, reflect, transmit some of the energy

- Radiation travels through space between particles

- Particles can absorb and re-emit energy

-Passes through gases easier

Homework: 23-35 on pages 164-165, Test Monday

Create a chart to compare the action of particles in conduction, convection, and radiation.

Controlling Heat

Thermoses

- Animals have special features to allow them to control heat

-What are some examples?

- Research an animal and how it keeps warm

Thermal Insulator

- reduces energy transfer between the contents and surroundings

- two glass walls with little air between them

- vacuum and glass are good insulators

-often coated with aluminum to be reflective, so less radiation can get in

- Material through which thermal energy moves slowly

- Gases are usually better thermal insulators than solids or liquids

-Fleece holds air close to you

-Insulation in buildings

- Matter is made up of particles

- Particles have kinetic energy because they are moving

- More kinetic energy makes an object feel hotter

- Temperature: The measure of the average kinetic energy of the particles that make up that object

- SI unit of temperature is Kelvins (K)

Thermal Energy

- Sum of kinetic energy and potential energy of all the particles that make up that object

- Depends on temperature

-Average kinetic energy of particles increases when temperature increases

- Thermal energy also increases when temperature increases

- If the mass of an object increases, the thermal energy of that object increases

Heating Systems Jigsaw

Homework: Read Lab on pages 160-161

Homework: Read 5.2, write down vocab

Come up with a solar powered house with as many solar powered things as possible.

Section 3 Review

Page 159

Thermodynamics

- Study of the relationships between thermal energy, heat, and work

- Heat and work increase thermal energy

- Example: Hands rubbing together, near fire, form a system

- System: Anything around which you can draw a boundary

Research experiments on thermal energy and work done by James Joule.

Convert Energy Mini Lab Page 156

What are three types of heating systems?

First Law of Thermodynamics

- If mechanical energy of a system is constant, the increase in thermal energy of that system equals the sum of the thermal energy transfers into that system and the work done on that system

- Two ways to increase the temperature of a system: heat the system or do work on the system

Doing Work to Transfer Thermal Energy

Come up with questions that could be used on the test.

Heat

Isolated and non-isolated sytems

- Thermal energy can be transferred from a cooler area to a warmer area if work is done in the process

- Refrigerators

- Air Conditioners

- Heat Pumps

- Isolated: No energy transfers between that system and its surroundings.

- Energy can change forms, but not enter or leave.

-Non-isolated: Energy can be transferred between the system and its surroundings

- Energy transferred between objects due to a temperature difference between the two objects

- Warmer objects always heat cooler objects

-Specific heat: amount of heat needed to raise the temperature of 1 kg of that material by 1 degree Celsius. Measured in Joules per kilogram degree Celsius (J/KgC)

- A high specific heat means it takes lots of heat to heat it up

What is temperature?

Second Law of Thermodynamics

- Approximately three-fourths of the chemical energy that is transformed into thermal energy in a car engine is never converted into mechanical energy

- Not very efficient

Converting Thermal Energy

- Energy spontaneously spreads from area of high concentration to areas of lower concentration

- Opposite process is not spontaneous

- Mechanical energy tends to transform into thermal energy

- Not possible to completely convert thermal energy into mechanical energy

- Heat engine: converts some thermal energy into mechanical energy

- Internal combustion engine: heat engine that burns fuel inside a set of cylinders

- A coolant is a substance that can absorb a great amount of thermal energy with little change in temperature

- Water is a useful coolant

- Thermal energy changes: Q is change in thermal energy, C is specific heat, Tf is the final temperature, Ti is initial temperature, Tf-Ti is temperature change

- Q = m(Tf-Ti)C

Section 1 review

- Page 142 Example Problem 1

- Practice Problems 1-3

- Scientists can calculate specific heat using a calorimeter.

-Read page 143 and summarize how to use a calorimeter

Test!

Homework: Read 6.1 and define vocab. Unit Presentations due December 4th

Physical Science Chapter 5: Temperature, Thermal Energy, Heat