Conduction Convection & Radiation Heat Transfer Conduction Convection & Radiation

WARM-UP: 03/14 Write today’s date and write the following information on your paper… ESSENTIAL QUESTIONS: How does heat travel? What are the effects of heat transfer? What are the similarities and differences between convection, radiation, and conduction? Objective: Students will understand that conduction, radiation and convection are methods of heat transfer, and that heat energy will travel in the direction of warmer to cooler temperatures.

Video Clip from Discovery Education https://app.discoveryeducation.com/learn/videos/8c8 fe28c-5d3a-4c95-9814- 28cb19e3c817?hasLocalHost=false Questions: What is a conductor? What is an insulator? What kind of heat transfer made the part of the nail that was not in the fire get hot?

Then you have witnessed heat, but how would you define it?? What is Heat? Ever feel the warmth from a fire? Touch a hot iron and burn yourself? Watch water boil on the stove? Then you have witnessed heat, but how would you define it??

What is Heat? Temperature is a Heat is the movement of energy from a warm object to a cool object. Energy passes through atoms Temperature is a measure of how much energy is in an object.

What is Heat? HOOK Try this… Rub your hands together for 30 seconds. Now touch them to your ears. Can you feel the heat transfer from your hands to your ears? As your ear warms, your hands will cool down until the particles in each reach the same speed.

How Does Heat Move? Heat moves through objects in three main ways: 1. Conduction 2. Convection 3. Radiation

Conduction When heat energy passes from one object to another when they touch Example: If you hold an ice cube in your hand the ice cube melts. The heat energy passes from your hand to the ice.

Conductors Some materials like to pass heat energy through them and do it easily. These materials are called conductors Metal and glass are two examples of conductors (You definitely don’t want to touch a metal pan when it’s on the stove!)

Insulators Materials that do not transfer heat energy easily or it may take longer for the heat to pass through them. Foam and plastic are both good insulators Example: plastic is normally used for coolers to keep heat from entering the container (which keeps your food cold)

Convection Convection deals with density. Heat energy can travel differently through liquids and gases: Convection is the transfer of heat by the movement of a heated fluid in a circular motion… Convection deals with density. REMEMBER: Density is the measure of how much mass is there in a volume of a substance. Example: Air circulating through your room, water boiling in a pot, and lava lamps are examples of convection

Convection When a liquid or gas is heated, the particles move faster and the density decreases. As the fluid becomes cooler, its density increases. As density increases, the fluid sinks. Heat Rises!!

Radiation When heat energy does not need to travel through particles it is known as radiation. Heat energy can travel through electromagnetic waves such as infrared, microwaves and visible light. Example: The heat from the sun travels by radiation

Look at the three images below Look at the three images below. Identify which is an example of conduction, convection, and radiation. A. B. C.

Look at the three images below Look at the three images below. Identify which is an example of conduction, convection, and radiation.

Heat Transfer Summarizer…

Heat Transfer Summarizer… Conduction Convection Radiation

Hand Boiler Toy The body heat from your hand causes the liquid to boil, which in turn makes the liquid evaporate, turning it to gas. The expanding gas pushes the liquid upwards and when you release your hand, equilibrium is re-established. The gas condenses into a liquid again and flows back into the lower bulb. What methods of heat transfer does this toy demonstrate? Explain.

Mr. Parr’s Heat Transfer Song https://www.youtube.com/w atch?v=wr8Z4SCETPs

Methods of Heat Transfer Worksheet Complete this worksheet for extra practice…Write down these definitions at the top of your paper. Conduction: Transfer of heat by direct contact of materials. Convection: Transfer of heat by the movement of a fluid. A fluid can be a liquid or a gas. Radiation: Transfer of heat through electromagnetic waves.