Vocabulary
The transfer of energy as electromagnetic waves.
Radiation
This method of heat transfer happens when two objects touch, and heat moves directly from the warmer object to the cooler one.
Conduction
Heat is always transferred to _________ objects to _________ objects until thermal equilibrium is reached.
warmer; cooler
When the temperature of an object increases, particle motion _____________.
Increases
You feel the hot sand on your feet as you walk barefoot along the beach. What type of heat transfer is happening between your feet and the sand?
Conduction
The energy of an object that is due to the object’s motion.
Kinetic Energy
This type of heat transfer occurs in liquids and gases as warmer, less dense particles rise and cooler, denser particles sink, creating a circular motion.
Convection
Give an example of two objects reaching thermal equilibrium.
Answers will vary.
Example: A mug of coffee on the counter will eventually reach the same temperature as the room around it.
When you exercise, there is an increase in what two types of energy?
Thermal and Kinetic
Boiling water would best represent which method of heat transfer?
Convection
The state in which objects in physical contact with each other have identical temperatures or exchange no energy as heat
Thermal equilibrium
You feel the Sun’s warmth on your face even though sunlight has to travel through space. What method of heat transfer is responsible?
Radiation
Ice melting in a glass of water is an example of heat transfer. Which object is gaining thermal energy and which object is losing it?
Ice- gaining
Water- losing
List the states of matter from greatest to least amount of kinetic energy.
Gas, liquid, solid
The total kinetic energy of a substance’s particles (vocab word)
Thermal energy
A measure of the average kinetic energy of the particles in an object.
Temperature
In a pot of soup heating on the stove, this method of heat transfer moves thermal energy from the burner to the pot, and another method moves energy through the soup itself. Name both methods.
Conduction and convection
Explain what is wrong with the following statement, and correct it.
When you hold an ice cube in your hand, coldness leaves the ice cube and enters your hand.
Coldness does not travel. Heat travels from areas of warm to cold. Heat is leaving your hand and entering the ice cube.
Rank these objects from fastest to slowest particle motion:
- Shoelace
- Popsicle
- Human body
- Fire
Fire, human body, shoelace, popsicle
Describe the differences between conduction, convection, and radiation.
Conduction- heat transfer through direct contact
Convection- heat transfer through differences in density usually through a liquid or gas
Radiation- heat transfer through electromagnetic waves
A set of interacting parts that work together; sometimes considered distinct from their surroundings only for the purpose of study.
System
A cup of hot cocoa sits on the counter. List one way that conduction, convection, and radiation could each be observed.
Answers may vary.
Possible answer:
Conduction- marshmallows melting in liquid
Convection- steam rising from the cup
Radiation- heat you feel on your face while drinking
Why does a metal object feel colder than a plastic object when they have both been outside and have the same temperature reading when scanned with an infrared thermometer?
Metal is a better conductor of heat and transfers heat away from your hand faster than plastic does. (Which is why it feels colder than plastic)
When we completed PhET Lab part 1, a girl pedaled on a bicycle which powered a generator and lit a light bulb. What energy transformations took place?
Chemical -> Mechanical -> Electrical -> Light and Thermal
*Thermal energy was also released from the girl pedaling
Your mom just finished baking cookies for a birthday party. She turned off the oven and left the oven door open. What will happen to the thermal and kinetic energy of the oven over the next 30 minutes?
Thermal energy and kinetic energy will both decrease. The oven will approach the temperature of the room.