A kettle of water is left to cool from 90 ∘C90\ ^\circ\text{C}90 ∘C to 30 ∘C30\ ^\circ\text{C}30 ∘C in a room at 20 ∘C20\ ^\circ\text{C}20 ∘C. Which statement describes the infrared radiation emitted by the water while it cools?
The water emits more radiation each second as its temperature falls.
The water emits less radiation each second as its temperature falls.
The water emits the same amount of radiation each second the whole time.
The water stops emitting radiation as soon as it reaches 30 ∘C30\ ^\circ\text{C}30 ∘C.
40 exam-style questions on AQA GCSE Physics 6.3 Black body radiation, covering 6.3.1 Emission and absorption of infrared radiation and 6.3.2 Perfect black bodies and radiation. Each one has a worked solution and a mark scheme showing where the marks go.