Thermal Energy Test Review Notes

Thermal Energy Test Review

Definitions

• Conduction: Transfer of thermal energy by the collision of particles; "direct contact".
• Convection: Thermal energy transfer due to differences in densities, occurs in gases & liquids.
• Radiation: Transfer of energy as electromagnetic waves, does not require a medium.

Types of Energy Transfer

• Conduction: Holding a mug of hot chocolate, Abby curls her hair each morning, An electric blanket keeps you warm, Touching hot pot handle on stove, Sand too hot to walk on with bare feet, A metal spoon in hot coffee, Ben wears a jacket to keep warm, Putting ice in a warm drink
• Radiation: Sitting next to campfire to get warm, Alligator sunbathing in the sun, Maisy’s snowman melted in sun, Sun heats the land during the day, Turtle gets hot from heat lamp, sitting by a campfire and warming up
• Convection: Attic gets hot during summer, Smoke rises up through chimney, Hot air balloon flies through sky, Using an air conditioner on a hot day, A dryer drying the wet clothes, Macaroni and cheese rise and fall in pot of boiling water, Kayla uses a hair dryer to dry her hair before school, lava lamp, ocean currents, Tectonic plate movement

Fill in the Blanks

• Heat is energy transferred by objects that are at different temperatures.
• Objects with the highest temperature always transfer heat to the object with the lowest temperature. This is why a hot mug of coffee makes your hand feel warm when you hold it.
• A major source of energy on Earth is radiation from the sun. The heat we feel travels directly to Earth in electromagnetic waves.
• Earth absorbs and reflects the sun’s energy.
• Energy is also transferred through conduction. Conduction is a direct transfer of heat through objects that are touching.
• In the atmosphere, air molecules transfer heat as they touch each other.
• Convection is the transfer of heat through the movement of a fluid. Liquids and gases can be fluids.
• In convection currents, warm air moves upward and cool air sinks downward.
• Radiation, Conduction and Convection work together to heat the troposphere. The movement of heat affects our temperatures, wind and precipitation.

Energy Transfer and Mediums

• Radiation does not require a medium (substance energy travels through).
• Radiation can occur in space because it does not need a medium to travel through.
• Thermal equilibrium: When the temperature of materials that are in contact are the same!

Thermal Energy Transfer

• Thermal energy travels from warmer objects to cooler objects.

  • Heat from air goes to ice water: Warm air moves to the cold ice water.
  • Warm air moves to the cold popsicle.
  • Warmer air moves into the cold fridge

• A cold drink from the refrigerator eventually reaches room temperature if left out on a table because heat transfers from the room temperature air to the cold drink, warming it up until it eventually reaches room temperature.

• A soccer ball would have more thermal energy than a paperclip at the same temperature because it has more mass.

States of Matter

• Solid
• Liquid
• Gas

Kinetic Energy and Temperature

• As the temperature of a substance or material increases, the average kinetic energy of the particles that make it up will increase.
• As the temperature of a substance or material decreases, the average kinetic energy of the particles that make it up will decrease.
• If a room temperature can of sprite is placed in the refrigerator, the average kinetic energy of the sprite’s molecules will decrease as the molecules slow down.
• If you place a kettle of water on the stove to make tea, the average kinetic energy of the water molecules will increase as the water molecules speed up.

Thermal Energy

• Energy transferred between two objects that are at different temperatures.
• Total kinetic energy of a substance's particles.
• When the temperature of materials that are in contact are the same.
• Transfer of thermal energy by the collision of particles.
• Is the transfer of energy by electromagnetic waves

Electromagnetic Radiation

• Used to describe all waves, ex. light, infrared, UV, Microwaves, etc.

Other Energy Transfer

• Thermal energy transfer in liquids or gases due to its motion.
• Convection and conduction need this in order to occur
• Is the energy of motion