Heat moves from warmer places to cooler places whenever there is a temperature difference. This lesson introduces the three methods by which heat transfer occurs and explains how materials and surroundings can affect the rate of transfer.
Conduction is heat transfer through matter by physical contact. The material does not move as a whole on a macroscopic scale, although its atoms and molecules are in thermal motion. Energy passes through interactions between neighboring particles.
All flashcards
What is conduction?
Conduction is heat transfer through matter by physical contact. The matter does not move as a whole on a macroscopic scale, though its particles are in thermal motion.
What is convection?
Convection is heat transfer by the macroscopic movement of a fluid, such as a liquid or gas. The moving fluid carries thermal energy from one place to another.
What is radiation as a method of heat transfer?
Radiation is heat transfer through emitted or absorbed electromagnetic waves, such as infrared radiation or visible light. It does not require matter between the source and receiver.
How does Earth receive heat from the Sun?
The Sun transfers energy to Earth by radiation. Electromagnetic waves can travel through the space between them without a material medium.
Name three ways people can influence the rate of heat transfer.
People can choose insulating materials, control air movement (for example, with weather stripping), and select surface colors that reflect or absorb sunlight.
Quiz questions
Heat travels from a hot electric burner into the base of a pan resting on it. Which method transfers the heat into the pan?Answer: Conduction through direct contact between the burner and pan.
A fan moves warm air from a furnace through a building. Which method primarily carries the heat?Answer: Convection carried by the moving air.
How does energy from the Sun cross the space between the Sun and Earth?Answer: Radiation carried by electromagnetic waves across space.
How does weather stripping around a door help limit heat transfer?Answer: It reduces air movement through gaps around the door.
Why can a white roof reduce energy absorbed from summer sunlight compared with a darker roof?Answer: It reflects more incoming sunlight.
Based on College Physics 2e by Paul Peter Urone, Roger Hinrichs (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.