Looking at a metal spoon in a warm drink, you might expect its handle to warm too. In sunlight, however, you can warm without touching the Sun. The result “becoming warmer” does not identify what happened along the way.
Connect a starting point to a destination. Ask whether matter occupies that path and whether the matter itself flows. Read the three exercises below by pairing the names conduction, convection and radiation with these features.
Energy travels along a rod without the rod flowing
The first exercise asks what mainly transfers heat along a metal rod heated at one end. Conduction passes energy from hotter to colder regions through matter without bulk flow. The rod itself does not flow from the heated end to the other end.
Among the options, convection involves flowing liquid or gas; thermal radiation uses electromagnetic waves. Evaporation changes liquid into gas and does not describe the path along this rod. Go beyond “because it is metal”: explain “through the rod, without the material flowing as a whole.”
Moving warm water carries energy by convection
In the second exercise, warm water moves and carries heat. A fluid is a material that flows, such as a liquid or gas; heat transport by its bulk movement is convection. The water itself moves, as well as energy. Compare that feature with the metal rod.
The specified flow cannot be relabeled conduction or thermal radiation. Nor is water flowing as a liquid the same as evaporation into gas. Do not select an answer from “warm” alone: use the words describing moving water carrying energy.
Can the Sun–Earth path cross empty space?
The third exercise specifies a path through the vacuum between the Sun and Earth. Radiation carries energy by electromagnetic waves, which can travel without matter such as air. Connect their arrival with energy being absorbed at Earth.
A matter-free gap supplies neither the material connection for conduction nor the moving fluid for convection. The friction option does not explain transport across that vacuum either. Instead of concluding “nothing can arrive,” ask which mechanism needs matter along its path.
Divide one scene into several paths
For water heated in a pan, draw one path through the metal base and another carried by flowing water inside. The first is conduction; the second is convection. Several mechanisms can operate in one scene, so avoid giving the entire pan scene a single label.
For paper practice, draw an arrow along a rod, an arrow following water flow and an arrow from the Sun to Earth. Label them “through matter without bulk flow,” “carried by flowing fluid” and “carried by electromagnetic waves.” Then revisit the three exercises. This is a paper exercise; no heating experiment is needed.
Continue from paths to conditions
No specialist prerequisite article or equation is needed here. After separating transfer mechanisms, continue to “Pressure and heat: reason from the conditions” for heat quantities and phase-change conditions. Practice following light in “Light paths: reflection, virtual images and refraction.”
The practice button selects basic, elementary-level questions on pressure and heat, including other matching questions beyond these three. Explain the path specified in each prompt before moving on, rather than recalling only an answer label.
TRY & READ
Check your understanding with examples
Compare the choices before opening the answer and explanation. Reading an example does not save a test answer or score.
Example 1 · Physics: pressure and heat
One end of a metal rod is heated. What mainly transfers heat along the rod?
Convection
Thermal radiation
Evaporation
Conduction
Read the answer and explanation
Answer: Conduction
Conduction transfers energy through the material without bulk movement of the material. Compare it with convection, where moving material carries energy: the rod transfers energy along its material without the rod itself flowing.
Definitions, laws and equations concerning heat and heat transfer.
Source checked: 2026-10-03, 2026-10-06
Example 2 · Physics: pressure and heat
What transfers heat when warm water moves from one place to another?
Evaporation
Convection
Conduction
Thermal radiation
Read the answer and explanation
Answer: Convection
Convection carries energy through the movement of a fluid. Here, a fluid means a liquid or gas that can flow. The comparison with conduction concerns whether material moves in bulk while transporting energy.
Definitions, laws and equations concerning heat and heat transfer.
Source checked: 2026-10-03, 2026-10-06
Example 3 · Physics: pressure and heat
How does energy from the Sun mainly reach Earth through the vacuum of space?
Conduction
Convection
Friction
Radiation
Read the answer and explanation
Answer: Radiation
Thermal radiation transfers energy through electromagnetic waves. These waves can travel without a material medium, so energy from the Sun can cross the vacuum of space and reach Earth. Conduction involves contact through matter, and convection involves moving fluid.
Read reasoning and more detail
Removing matter from the path prevents those two mechanisms, but it does not prevent radiation.
Vapor pressure, saturation, evaporation and boiling.
Source checked: 2026-10-23
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Topics: Physics: pressure and heat. Range: Everyday knowledge. Difficulty: Basic. These are selected initially. You can change these on the setup screen.
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Draw a normal, distinguish reflected rays from backward extensions, and follow light entering glass. Revisit three examples through one consistent diagram method.