Physics · Black body radiation (physics only)
Every mark from 2 to 6
3real answers to the same question, each marked for real by MarkMatch’s AI marker — not invented scores.
The Earth receives radiation from the Sun and emits infrared radiation into space. Over a long period, the Earth's average temperature remains approximately constant. Explain how: - the balance between radiation absorbed and radiation emitted affects the Earth's temperature; - the Earth could become warmer if it absorbed radiation at a greater rate than it emitted infrared radiation.
Level 3 (5-6): Relevant points (reasons/causes) are identified, given in detail and logically linked to form a clear account. Level 2 (3-4): Relevant points (reasons/causes) are identified, and there are attempts at logically linking. The resulting account is not fully clear. Level 1 (1-2): Points are identified and stated simply, but their relevance is not clear and there is no attempt at logical linking. No relevant content (0).
The Sun gives the Earth heat and space takes some heat away. If it gets too hot it might lose heat, and if it gets too cold it might gain heat, so its temperature stays about the same. If it absorbs more radiation it will get warmer.
What this answer missed
- •equal rates of radiation absorption and infrared emission mean that the Earth's total energy stays constant and its average temperature remains approximately constant
- •absorbing radiation at a greater rate than it emits gives the Earth an overall energy gain, causing its temperature to rise
- •as the Earth becomes hotter, it emits more infrared radiation, so its temperature stops increasing when the emitted rate becomes equal to the absorbed rate
The Earth absorbs radiation from the Sun, which makes it warmer, and emits infrared radiation into space, which cools it. Its temperature stays constant when these are balanced. If it absorbed more than it emitted, it would warm up.
What this answer missed
- •There is an overall gain in energy when the Earth absorbs radiation faster than it emits, so its temperature increases; as it becomes hotter, it emits more infrared radiation until the emitted rate becomes equal to the absorbed rate.
The Earth continuously absorbs radiation from the Sun and emits infrared radiation into space. If the rate absorbed is equal to the rate emitted, the energy of the Earth and therefore its average temperature remain approximately constant. If the Earth absorbs radiation at a greater rate than it emits, there is an overall increase in energy, so its temperature rises. This would continue until the rates were balanced.
- •The Earth absorbs radiation from the Sun and emits infrared radiation into space.
- •When the rates of radiation absorbed and emitted are equal, the Earth's energy and average temperature remain approximately constant.
- •When the Earth absorbs radiation at a greater rate than it emits, there is an overall increase in energy.
Want your own answers marked like this, for real?
Try it on MarkMatch →Or read the full Black body radiation (physics only) revision notes first.