Energy Transfers Lessons

​Hello students we are going to start incorporating technology into our lessons more often. We will begin by reviewing some things from our lessons on thermal energy.

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Make sure that you take the time to go through this lesson fully and watch all the videos where you will have a good understanding of the lesson.​

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Our next lesson will cover Ocean Currents and Wind. You will need a good understanding of energy transfer in the form of heat to be successful in these units.​

​Temperature!!! What is Temperature???

​Temperature in non-scientific terms is a measure of how hot or cold something is.

​In science we learn that Temperature is the average kinetic energy of particles in a substance!!!

​Remember that all matter is made up of particles that are in constant motion!!!!!

​Since the particles of a substance are in constant motion, each of those moving particles have kinetic energy.

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Temperature is an average of the kinetic energy of all ​the moving particles in substance. This gives you a certain temperature in degrees.

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​High Temp

​Low Temp

​Thermal Energy!!! What is Thermal Energy???

​Thermal energy is the total kinetic energy of particles in a substance.

​Still Confused? Well Lets look into it more!!!

​Remember that all matter is made up of particles that are in constant motion!!!!!

​Since the particles of a substance are in constant motion, each of those moving particles have kinetic energy.

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Thermal energy is the total or sum of the kinetic energy of all ​the moving particles in substance.

​High Thermal Energy

​Low Thermal Energy

​How does Kinetic Energy, Temperature and Thermal Energy All Relate to each other?

​THIS IS HOW!!!!

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​1. As the particles of a substance or object start to move faster they begin to gain more kinetic energy!!!

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2.​ As the kinetic energy of the particles in a substance rise the temperature of that substance rises!!!

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3. When​ the temperature of a substance rises the thermal energy of that substance rises!!!

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​High Temp

​Low Temp

​High Thermal Energy

​Low Thermal Energy

​High Kinetic Energy

​Low Kinetic Energy

​How does Kinetic Energy, Temperature and Thermal Energy All Relate to each other?

Fill in the Blanks

Fill in the Blanks

​What is the difference between Temperature and Thermal Energy ???

​Here is the difference!!!

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​1. Temperature of a substance is only dependent on the kinetic energy of the particles of a substance.

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2. Thermal Energy is dependent on the kinetic energy of particles in a substance and the number of particles a substance has.

​What is the difference between Temperature and Thermal Energy ???

​Still confused???

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For e example​, in the case of thermal energy if you have two objects that are the same temperature and have the same masses (amount of particles) the object with the greatest temperature will have more thermal energy!!!!!

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However if you have two objects that are the same temperature but have different masses (amount of particles) the object with the greatest mass will have more thermal energy!!!!!​

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​If you have two objects that are the same temperature but have different masses (amount of particles) the object with the greatest mass will have more thermal energy!!!!!

Multiple Choice

Which object has the greatest thermal energy?

• Beaker A

• Beaker B

• Beaker C

Multiple Choice

Which beaker has the greatest thermal energy??

• Beaker A (6 oz.)

• Beaker B (12 oz.)

​What is Heat???

​Now that we have an understanding of thermal energy we can learn about heat!!!

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1. Heat is the transfer of thermal energy from one object to another!!!

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2. Heat only transfers between objects that are at different temperatures!!!​

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3. When two objects reach the same temperature heat stops flowing between those objects. ​​

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​What is Heat???

​ ​​Heat only transfers in one direction!!!!!

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​When two objects come into contact Heat (thermal energy) always transfers from the object with the higher temperature to the object with the lower temperature!!!!

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Example.. ​

​In this image the fire has a higher temperature than the hands!!!!

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​Therefore heat (thermal energy) is being transferred from the fire to the hands.

Multiple Choice

In which direction is heat (thermal energy) being transferred???

• Heat (thermal energy) is being transferred from the flame to the metal rod.

• Heat (thermal energy) is being transferred from the metal rod to the flame.

Multiple Choice

In what direction is heat (thermal energy) being transferred?

• Heat is being transferred from the spoon to the coffee.

• Heat is being transferred from the coffee to the spoon.

​How is heat transferred between objects???

​I'll tell you how!!!

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Heat is transferred between objects through three processes.

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1. Conduction - Transfer of heat (thermal energy) between objects through direct contact.

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2. Radiation - Transfer of heat (thermal energy) between objects through electromagnetic waves.

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3. Convection​ - Transfer of heat (thermal energy) between objects through the movement of liquids and gases.

​Conduction

​Conduction - Transfer of heat (thermal energy) between objects through direct contact.

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Examples... ​

​1. Heat is transferred from the handle of the pot to the hand because they are touching.

2. Heat is transferred from the iron to the hand be​cause they are touching.

​Radiation

​Radiation - Transfer of thermal energy between objects through electromagnetic waves.

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Note: Objects do not have to touch for heat to transfer through radiation.​

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Examples..... ​

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​1. Heat is transferred from the sun to the snowman through the movement of electromagnetic waves.

2. Heat is transferred from the fire to the hands through the movement of electromagnetic waves.

​THE INFORMATION ABOUT CONVECTION IS VERY IMPORTANT TO OUR NEXT LESSON SO PAY CLOSE ATTENTION!!!!!!!!!!!!!

​Convection

​Convection​ - Transfer of thermal energy between objects through the movement of liquids and gases.

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Examples.... ​

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​1. Heat is transferred from the handle of the pot to the hand because they are touching.

2. Heat is transferred from the iron to the hand be​cause they are touching.

​1. Heat (thermal energy) is transferred through the movement of water molecules.

2. Heat (thermal energy) is transferred through the movement of air molecules.

​How does convection happen? What causes the movement?

​I'll tell you how!!!!

​This happens because of differences in the temperature of liquids and gases in a substance.

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1. HOT AIR/LIQUIDS RISE 2. COLD AIR/LIQUIDS SINK​

​I'LL tell you why!!!!

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Hot air/liquid rises and ​cold air/liquid sinks because of differences in DENSITY.

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​Why does hot air rise and cold air sink????

​Hot gas/liquid is less dense (has less compacted particles) so it rises.

Cold gas/liquid is more dense (has more compacted particles) so it sinks.​

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​This causes movement in gas and liquids called a convection current.

Multiple Choice

A microwave warms up a piece of leftover pizza... The pizza is being warmed up by which type of heat transfer?

• Conduction

• Convection

• Radiation

Multiple Choice

You just burnt your elbow on the hot metal part of the seatbelt in a car (OUCH!!)

Your elbow was warmed up through which type of heat transfer?

• Conduction

• Convection

• Radiation

Multiple Choice

The liquid in this lava lamp is heated through what type of heat transfer?

• Conduction

• Convection

• Radiation

Multiple Choice

The radiator (heater) warms up the room through what type of heat transfer?

• Conduction

• Convection

• Radiation

Multiple Choice

True Or False

Cold Air/Liquids Rises

&

Hot Air/Liquids Sink

• True

• False

Multiple Choice

Which beaker contains water with the highest density??

• Beaker A

• Beaker B

• Beaker C

Multiple Choice

Which beaker contains water with the lowest density??

• Beaker A

• Beaker B

• Beaker C

Multiple Choice

Which State of Matter has the lowest Density

• Solid

• Liquid

• Gas

​What Is Thermal Expansion

​Thermal Expansion is the increase in the size of a substance in response to an increase in the temperature of the substance.

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Example....​

​When a gas or liquid is heated the particles in that substance move apart from each other and expand. (They become less dense)

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When a gas or liquid is cooled the particles in that substance move closer to each other and become compacted.

(They become more dense) ​

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Multiple Select

The hot air balloon rises because of which process?

(There are 2 Answers)

• Conduction

• Convection

• Radiation

• Thermal Expansion

​What is Atmosphere???

​Atmosphere is a mixture of gases that surround a planet or moon.

​The atmosphere contains the air that we breathe; protects us from the harmful radiation of the Sun; helps to keep the planet's heat on the surface, and plays a very important role in the water cycle.

​ Why is the Atmosphere Important to Us