February 10 th and 11 th Unit 6: Energy Transformations Knowledgeable Objective(s): 1.SWBAT distinguish when conduction, convection, and radiation is occurring. 2.SWBAT explain how thermal energy transfer happens and at what point it will stop. Relevance: Do Now: Four Square Do Now MATERIALS NEEDED: 1.Pencil 2.Unit 6, Day 2 Packet 3.Agenda

StudyJams Video Questions: 1.What is the difference between heat/thermal energy and temperature? Thermal energy tells how quickly the particles are moving and temperature is just a measurement of thermal energy. 2.Energy can’t be created or destroyed. 3.What are the three ways heat is transferred? Radiation, conduction, and convection. 4.What is one example of radiation? The sun is an example of radiation through electromagnetic waves. 5.During conduction, heat is always transferred from the hot to the cool object. 6.Convection is the transfer of heat through a liquid or gas.

What is Thermal Energy? Thermal energy is the total amount of kinetic energy contained in all the particles of a substance. The greater the kinetic energy of the particles in the substance, the more thermal energy the substance has. The more particles a substance contains, the greater the thermal energy. How fast do you think the particles move in solids, liquids, and gases?

Heat vs. Temperature The term heat is commonly used in place of the term thermal energy. However, Heat is the transfer of thermal energy between substances that are different temperatures. Temperature is just a measurement of heat/thermal energy. We measure heat in Degrees Celsius (°C) or often Kelvins (K).

What are the relationships among thermal energy, heat, and temperature? Stop and Jot/Turn and Talk What do you think happens when an object’s temperature increases or decreases?

Watch out! Thermal energy, heat, and temperature are not the same thing! Thermal energy is the total amount of kinetic energy contained in the particles of substances. Temperature is the measurement of that kinetic energy. Heat is the transfer of that thermal energy from one substance to another.

30 sec! Word Scramble Challenge! ERPATUETMRE Definition: The measurement of thermal energy contained in an object. TEMPERATURE Definition: The measurement of thermal energy contained in an object.

Methods of Heat Transfer There are 3 methods of thermal energy transfer – Conduction – Convection – Radiation

Conduction DEFINITION: – Conduction is the transfer of heat from a warmer substance to a cooler substance through direct contact. EXAMPLE: – Touching the handle of a hot pan PICTURE: – Draw a picture to help you remember conduction HAND SIGNAL: Clap hands together to show direct contact

Conduction

Convection DEFINITION: – Convection is the transfer of heat through currents in liquid or gas. EXAMPLE: – Suppose you place a pot of cold water on a hot stove. As the water at the bottom of the pot heats up, it becomes less dense. Because the warm water is less dense than the cold water above it, the warm water rises and displaces the cold water. The cold water then sinks. – The movement of water results in a convection current that transfers thermal energy throughout the pot. PICTURE: – Draw a picture to help you remember convection HAND SIGNAL: Circling your arms to show a current

Convection

Watch out! Convection only occurs in fluids – liquids and gases. Convection cannot occur in solids. The particles are moving from one part of the material to another (i.e. boiling water)

Radiation DEFINITION: – The transfer of energy as electromagnetic waves (waves that travel through space) – Radiation can occur through empty space EXAMPLE: – The Sun heats the Earth through the process of radiation. PICTURE: – Draw a picture to help you remember radiation HAND SIGNAL: Wiggling fingers to show waves

Radiation

Watch out! Radiation can occur in solids, liquids, gases and a vacuum. Transferring through a vacuum means they do not need to pass through matter or particles. Radiation can happen in space! Conduction and convection cannot.

In what three ways is heat transferred? Think-Pair-Share What type of heat transfer cannot take place in solids? Explain

30 sec! Match ‘em Up! A.Conduction B.Convection C.Radiation 1.The transfer of heat through empty space and electromagnetic waves. 2.The transfer of heat through direct contact. 3.The transfer of heat through currents of liquid or gas.

So, which is it? Convection

So, which is it? Conduction

So, which is it? Radiation

So, which is it? Conduction

So, which is it? Convection

So, which is it? Radiation

Imagine if… Suppose you place an ice cube in a glass of lemonade on a hot day. After awhile, the lemonade starts to feel cold and you notice the ice has started to melt. What has happened to the thermal energy of both substances?

Thermal Energy Transfer When two objects come into contact with one another, heat will transfer (flow) from the object with the warmer temperature to the object with the colder temperature. The heat continues to flow until the temperature of the two objects reach the same temperature. This is also known as equilibrium.

Imagine if… Suppose you place an ice cube in a glass of lemonade on a hot day. After awhile, the lemonade starts to feel cold and you notice the ice has started to melt. What has happened to the thermal energy of both substances? The water’s thermal energy is transferred to the ice which causes it to melt!

What does it mean for two objects’ temperature to reach equilibrium? Turn and Talk

What happens to the transfer of thermal energy as heat when thermal equilibrium is reached Stop and Jot

Demonstration Let’s take a look at a simulation of the way heat transfer happens. While I demonstrate, you will be taking answering guided questions on a sheet of notebook paper. 10 min

Demonstration 1.What do you notice about the starting temperatures of all the objects? What is this often called? 2.What happens to the thermal energy as the brick/iron is cooled? 3.What happens to the thermal energy as the water is heated up? 4.What happens to the thermal energy of both objects when the brick/iron is added to the pot of water? 5.When does the transfer of thermal energy stop between both objects? 10 min

Independent Practice Complete the independent practice about heat transfer. During this time you should be working silently and independently. If you have a question, please raise your hand silently at your seat. 15 min

Complete the exit ticket silently. Turn in as you leave. You may pack up your things. Exit Ticket

STOP Cards SSummarize: Summarize the day’s lesson and what we learned. TTrait: What IB trait relates to the lesson? OObjective: Re-state in your own words and say whether or not we met that objective for the day. PPurpose: What was the purpose of this lesson?