Heat and Temperature

Page 1: Introduction to Heat

• Definition of Heat:

  • Heat is a form of energy that transfers from one object to another due to a difference in temperature.

  • Heat flows from warmer objects to cooler ones.

• Heat & Temperature Reflection:

  • What do you already KNOW about heat and temperature?

  • What are you WONDERING about heat and temperature?

  • What have you LEARNED about heat and temperature?

  • To be completed at the end of the unit.

• Activity:

  • Rub your hands together quickly for 15 seconds.

  • Describe the sensation.

  • Where does the heat come from?

  The heat generated comes from the friction created between your hands as they move against each other, which converts kinetic energy into thermal energy, warming your skin.

• Ways heat transfers include conduction, convection, and radiation. Each method plays a crucial role in how heat moves through different environments and affects our surroundings.

  Conduction: Direct contact (e.g., a metal spoon in hot soup). Transfers heat between solids, liquids, or gases.

• Convection: Heat transfer through fluids (e.g., warm air rising).

• Radiation: Heat transfer through electromagnetic waves (e.g., the sun heating the Earth) without involving particle movement.

Page 2: Understanding Heat Transfer

• Types of Heat Transfer:

  1. Fill in the Blanks:

     • Can heat do work? _______________

     • What type of heat cooks pancakes? ____________________

     • What type of heat cooks fruit? ____________________

     • What type of heat roasts marshmallows? ____________________

• Conceptual Questions:

  • Do cold things have heat?__________

  • Do the molecules in cold things move fast or slow? _______________

  • Which material conducted heat better with butter on the knife? ____________________

  • Which had more heat energy – the match or the ice sculpture? __________________________________

  • Infrared camera color for hot objects? ________

  • Infrared camera color for cold objects? _________________

  • How many air molecules are in a vacuum? __________________________________________________

  • Conduction, convection, or radiation in the fireplace? ___________________________________

  • Where does the warm air go when you have a fire in a fireplace? ______________________________

  • Properties of Heating Elements Used in Baking:

    • Metal pan? _______________________________________________

    • Glass pan? ________________________________________________

• How is heat energy measured? ____________________________________________________________

• Body Heat Dispersion:

  • Where does the heat your body gives off go? __________________________________________________________

Page 3: Types of Energy

• Various Types of Energy:

  • Thermal: Total energy of the particles in a solid, liquid, or gas.

  • Magnetic: Causes some types of magnets to attract or repel each other.

  • Light: A type of energy we can see.

  • Gravitational: Stored energy of an object when above Earth’s surface.

  • Nuclear: Energy released from the nucleus of atoms, produced by fission or fusion.

  • Electrical: Energy from charged particles that causes action or movement.

  • Elastic: Energy stored due to the deformation of elastic objects.

  • Sound: Energy produced by the movement of vibrations through matter.

  • Mechanical: Energy an object acquires when work is done on it.

Page 4: Temperature Scales

• Common Temperature Scales:

  • Celsius (°C)

  • Fahrenheit (°F)

  • Kelvin (K)

• Conversion Activities:

  1. Convert 10℃ to Fahrenheit.

  2. Convert 310K to Celsius.

• Temperature Measurement:

  • Temperature is measured using various types of thermometers:

    • Liquid-in-glass thermometers: Medical and weather measurements.

    • Industrial thermometers: Used in industry and food safety.

    • Laboratory thermometers: Used in science experiments.

  • A liquid-in-glass thermometer uses a liquid (like mercury or alcohol) that expands and rises as temperature increases, and contracts when temperature decreases.

Page 5: Thermal vs. Temperature Energy

• Definitions:

  • Thermal Energy: Measure of total energy of all particles in a substance.

  • Temperature: Measure of average energy of all particles in a substance.

• Calculating Thermal Energy:

  • ADD the values for all particles together.

• Calculating Temperature:

  • ADD all values together

  • DIVIDE by the number of particles.

Page 6: Heat Transfer Mechanisms

• • Conduction Lab:

    • Compare heating rates of metal vs. plastic spoons in hot water.

    • Explanation: Why does metal conduct heat better than plastic?

  • Convection Demonstration:

    • Observe movement of food coloring in hot and cold water.

    • Explanation: What happens to the warm and cold water? Why?

Page 7: Conductors and Insulators

• Conductors:

  • Materials that allow heat transfer. Good conductors have little space between particles (highly compact).

  • Examples include:

    • Metals

    • Water

    • Plastic (poor conductor)

    • Air (poor conductor)

• Definition of Conductivity:

  • A material’s ability to transfer heat via conduction.

• Insulators:

  • Materials that do not allow heat transfer, having a lot of space between particles (not very compact).

  • Examples include:

    • Rubber

    • Wood

    • Fabric

• Electromagnetic Spectrum Absorption:

  • Light & Shiny Surfaces → Reflect infrared wavelengths.

  • Dark & Dull Surfaces → Absorb infrared wavelengths.

Page 8: Energy Transfer Processes

• Heat Transfer Scenarios:

  • Write down whether the main energy transfer process in each scenario is conduction, convection, or radiation.