Bellringer: March 10, 2016 Heat transfers from _____ to _____. _____ is the transfer of heat that occurs when two objects of different temperatures touch. Convection is the transfer of heat within fluids or air by the movement of _____ currents within a fluid or gas.

Bellringer: March 11, 2016 Heat transfer stops when _____. The movement of heat from one substance to another is called ____ ___. ______ is the way heat moves through empty space.

Unit 6: Energy Conservation And Transfer Objective: Understand characteristics of energy transfer and interactions of matter and energy. 6.P.3

Upon completion of this unit, students will be able to: Illustrate the transfer of heat energy from warmer objects to cooler ones using examples of conduction, radiation, and convection and the effects that may result. Explain the suitability of materials for use in technological design based on a response to heat (to include conduction, expansion, and contraction) and electrical energy (conductors and insulators).

Forms of Energy Thermal energy: when a warmer object is in contact with a cooler one Mechanical energy: when two objects push or pull on each other over a distance Electrical energy: when an electrical source such as a battery or generator is connected in a complete circuit to an electrical device Electromagnetic waves: form of energy that includes radio waves, microwaves, X-rays and gamma rays, as well as visible light. (waves which can travel through the vacuum of outer space)

Difference between Heat and Temperature Heat- is the total energy of the atoms/ molecules within a substance. Heat energy is related to a substance’s mass. Measured in Joules (Unit of energy) Measured by Calorimeter Temperature: is a measure of the hotness or coldness of a substance or Measured in Kelvin, Celsius, or Fahrenheit. Measured by a thermometer

Heat and Temperature Looking at the following images: -Where does the energy flow from? -Which “image” sees a temperature rise?

Look at the picture of the kettle and the fire. Think about: one of the sparks from the fire and the kettle full of boiling water. Q. Which has the highest temperature – spark/kettle of water? Q. Which has the most heat energy – spark/kettle of water? https://www.youtube.com/watch?v=v1zOnyC4RgQ Or https://goo.gl/wb78JV

How does thermal energy transfer? https://www.youtube.com/watch?v=6sUOMds_zmE Or https://goo.gl/3DcBVV Heat transfers from hot to cold. Heat can transfer three ways: 1) Conduction 2) Convection 3) Radiation

Conduction Conduction: transfer of heat between substances that are in direct contact with each other. Conduction occurs when a substance is heated, particles will gain more energy, and vibrate more. These molecules then bump into nearby particles and transfer some of their energy to them. This then continues and passes the energy from the hot end down to the colder end of the substance. The better the conductor, the more rapidly heat will be transferred. Metal is a good conduction of heat.  http://app.discoveryeducation.com/player/view/assetGuid/D0532549-2AFD-42B9-9E66-A9FE80E84B28 Or https://goo.gl/gBMTgM Thermal Energy

Convection Convection occurs when warmer areas of a liquid or gas rise to cooler areas in the liquid or gas. Cooler liquid or gas then takes the place of the warmer areas which have risen higher. This results in a continuous circulation pattern. Water boiling in a pan is a good example of these convection currents. Another good example of convection is in the atmosphere. The earth's surface is warmed by the sun, the warm air rises and cool air moves in. https://app.discoveryeducation.com/learn/videos/77abfc0e-a5ce-442f-b4c7-2fb81be6b319?hasLocalHost=true OR https://goo.gl/xF4Ei7

How is convection helping here?

How does the sun’s heat energy reach us?

Radiation Radiation is a method of heat transfer that does not rely upon any contact between the heat source and the heated object. No mass is exchanged and no medium is required in the process of radiation. Heat can be transmitted through empty space by thermal radiation often called infrared radiation. This is a type electromagnetic radiation. Examples of radiation is the heat from the sun, or heat released from the filament of a light bulb. Everything gives off heat radiation. The hotter the object, the greater the energy of the radiation. https://app.discoveryeducation.com/learn/videos/5e37002e-255b-4449-9172-2535bd9d0c92?hasLocalHost=true OR https://goo.gl/FSVfHU

When does heat transfer end? Heat flows through materials or across space from warm objects to cooler objects until both objects are at equilibrium.

Video: Heat Transfer http://studyjams.scholastic.com/studyjams/jams/science/energy-light-sound/heat.htm OR https://goo.gl/UrbTAl

Teach it to a friend!! Take 2 minutes and share with your neighbor what the 3 methods of heat transfer are. (Convection, Conduction, and Radiation)

Heat Transfer Foldable

What is ENERGY? Energy is the ability to do work. Everything that happens in the world uses energy! Most of the time we cannot see energy, but it is everywhere around us! Is NEVER created or destroyed! Can only be stored or transferred.

Batteries store energy! This car uses a lot of energy! We get our energy from FOOD! Even this sleeping puppy is using stored energy!

Two Types of Energy Potential Energy: Stored energy that results from the position or shape of an object. Kinetic Energy: Energy that an object has due to its motion.

Potential and Kinetic Energy?

What are Conductors and Insulators? Have you ever stepped from a rug to a tile floor on a cold morning? The tile floor feels colder than the rug. Why? The difference between the rug and the floor is how well a material conducts heat.

Conductors A conductor transfers thermal energy well. Includes materials that carry electricity. Metals, such as silver and stainless steel, are good conductors. A metal spoon conducts heat better than a wooden spoon.

Conductors Some materials are good conductors because of the particles they contain and how those particles are arranged.

Insulators An insulator does not transfer thermal energy well. Insulation prevents heat from entering a building in hot weather and from escaping in cold weather. Wood, wool, straw, and paper are good insulators. Gases in the air also act as insulators.

Insulators

Bill Nye the Science Guy: HEAT Video: https://www.schooltube.com/video/f04c2c2cf7d34977918c/Bill%20Nye%20Heat

Bellringer: March 15, 2016 A(n) __________ transfers thermal energy well. __________ energy is energy that an object has due to its motion, while __________ energy is stored energy. A(n) __________ does not transfer thermal energy well..

Thermal Contraction As the average energy (temperature) of particles decrease, the space between the particles decreases. Matter in the solid, liquid, and gas phase CONTRACTS!

Thermal Expansion As the average energy (temperature) of particles increase, the space between the particles increases. Matter in the solid, liquid, and gas phase EXPANDS!

Steel Bridges Expansion joint strips in bridges allow for the bridge to expand in hot weather and not break. These same joint strips allow for the bridge to contract in cold weather and not break.

Teach it to a Friend!! Take 2 minutes and teach your neighbor the difference between conductors and insulators.

Video: Conductors and Insulators https://app.discoveryeducation.com/mycontent

Classwork http://duch.sd57.bc.ca/~rmcleod/Chemists_Corner/Sc9_-_T2_-_W2_files/7.2%20Worksheet.pdf

Good resource http://burnet.twpunionschools.org/subsites/slama/documents/8th%20Grade%20Science/Workbooks/Chapter%2005.pdf Writing prompts http://scienceideas.org/TeacherResources/BinderEnergy/Tab3/Writing-prompts.pdf

Uses of Heat Read pg. 633 aloud. The transformation of thermal energy to mechanical energy requires a device called a heat engine. This is generated from the use of combustion. Combustion chemical energy that is stored in fuel is burned. (Coal and Gasoline)

Uses of Heat Read pg. 634 aloud. Engines that burn fuel outside the engine in a boiler are called external combustion engines. Example is a steam engine. Coal or oil heats water in a boiler and the steam produced provides energy.

External Combustion Engine

Uses of Heat Engines that burn fuel in cylinders inside the engines are called internal combustion engines. Diesel and Gasoline engines are examples. Spark ignites the fuel which causes explosion to provide the energy.

Internal Combustion Engines

Teach it to a Friend!! Take a few minutes to teach your neighbor what the two main types of heat engines are. Describe characteristics of each.

Uses of Heat Read pg. 636-637 aloud. A refrigerator is a device that transfers thermal energy from inside the refrigerator to the room outside. Air conditioners work the same way as refrigerators, however it absorbs heat from the air inside a room/car and transfers it to outdoors.

Refrigerator Cycle

Video Clip https://app.discoveryeducation.com/mycontent#MyContent/Favorites Steam Engine Clip Internal Combustion Clip

Classwork Answer Question 1 (A-C) on page 637 in textbook. PLEASE WRITE THE QUESTION! 

Classwork (slide 9)

Convection Demonstration http://goo.gl/BKCgTQ