How does the infrared radiation emitted in a given time change as an object becomes hotter?

It increases, because the hotter the object the more infrared radiation it radiates in a given time.

Does a block of ice emit any infrared radiation?

Yes, because every object emits infrared radiation, although a cold object emits less than a hot one.

Why would a perfect black body also be the best possible emitter of radiation?

Because a good absorber of radiation is also a good emitter.

A radiator is painted matt black rather than shiny silver. Explain the effect on the radiation it gives out.

A matt black surface is a better emitter, so it radiates more infrared radiation in a given time.

AQA GCSE Physics 8463

Atomic Structure

Topic overview The structure of an atom Mass number, atomic number and isotopes From the plum pudding model to the nuclear model Chadwick, the neutron, and comparing the models Radioactive decay and nuclear radiation Nuclear equations Half-lives and the random nature of radioactive decay Radioactive contamination Background radiation Uses of nuclear radiation, and how half-life affects hazard Nuclear fission and nuclear fusion

Electricity

Topic overview Circuit symbols, electrical charge and current Current, resistance and potential difference Ohmic conductors, filament lamps, diodes and thermistors Light-dependent resistors, and investigating resistance Current and potential difference in series and parallel Constructing circuits, and calculating in series circuits Direct and alternating potential difference, and mains electricity Power and efficiency Appliances, and the energy transferred by electrical work Power, and the power ratings of domestic appliances The National Grid Static charge Electric fields

Energy

Topic overview Energy stores and systems Kinetic energy Elastic and gravitational potential energy Energy changes in systems Power Energy transfers in a system The main energy resources, renewable and non-renewable Environmental impact and trends in energy use

Forces

Topic overview Scalars, vectors, forces and the resultant force Gravity Work done and energy transfer Stretching, compressing, and the spring constant Linear and non-linear extension, and work done on a spring Moments, levers and gears Pressure at a surface, and the equation p = F over A Atmospheric pressure Distance, displacement and speed The speed of sound, and the distance-speed-time equation Velocity and the distance-time relationship Acceleration, deceleration and velocity-time graphs Area under a velocity-time graph, and the uniform acceleration equation Newton's First Law Newton's Second and Third Laws Stopping distance and reaction time Factors affecting braking distance Braking force, deceleration and the dangers of stopping quickly

Magnetism and Electromagnetism

Topic overview Poles of a magnet Magnetic fields around a magnet The compass, and plotting a magnetic field Electromagnetism

Particle Model of Matter

Topic overview Density of materials Changes of state and internal energy Temperature changes in a system and specific heat capacity Changes of state and specific latent heat Particle motion in gases Pressure in gases, volume and temperature

Space Physics

Topic overview Our solar system, and the orbits of satellites The life cycle of a star Red-shift

Waves

Topic overview Transverse and longitudinal waves, and the wave equation Wave properties, and refraction at a boundary Reflection of waves Types and uses of electromagnetic waves Radio waves, and the hazards of ultraviolet, X-rays and gamma rays Lenses Visible light Emission and absorption of infrared radiation, and black bodies

Waves

Emission and absorption of infrared radiation, and black bodies

3 things to know
Paper 2

Overview

How every object emits and absorbs infrared radiation and how the amount rises with temperature, what a perfect black body is and why it is the best emitter, painting a radiator matt black, how the intensity and wavelengths of emitted radiation change as an object gets hotter, and why objects at room temperature do not glow.

What you need to know

Answer each one before you reveal it.

Your recallNot started

Key term

Describe how the radiation given out by an object changes as it gets hotter, using a heated metal bar as an example.

Key term

Which objects emit and absorb infrared radiation?

Key term

What is a perfect black body?

Questions from this subtopic

Each one with the model answer underneath.

1
Which objects emit and absorb infrared radiation?
Model answer
All objects do, whatever their temperature.
2
How does the infrared radiation emitted in a given time change as an object becomes hotter?
Model answer
It increases, because the hotter the object the more infrared radiation it radiates in a given time.
3
Does a block of ice emit any infrared radiation?
Model answer
Yes, because every object emits infrared radiation, although a cold object emits less than a hot one.
4
What is a perfect black body?
Model answer
An object that absorbs all of the radiation that falls on it.
5
Why would a perfect black body also be the best possible emitter of radiation?
Model answer
Because a good absorber of radiation is also a good emitter.
6
A radiator is painted matt black rather than shiny silver. Explain the effect on the radiation it gives out.
Model answer
A matt black surface is a better emitter, so it radiates more infrared radiation in a given time.

See the rest and revise

Other ways to work this

The same content, four other ways.

What is inside Levo

Six ways to work the same material.

1Closed book

2Open book

3Closed book

See a huge jump in your memorisation

Answer cold, learn it, then prove it stuck. Levo tracks the jump between your first attempt and your last.

Atomic Structure

Electricity

Energy

Forces

Cram a whole paper in one sitting

Sort every topic into what you know and what you do not, then drill only the weak ones.

A wave.

transverselongitudinalmechanical

Blank Blitz consolidates the facts

Rapid timed gap-fills on the terms and numbers you need to recall without thinking.

AA cloud of dust and gas in space.

BThe force of gravity pulls the material together.

CThe material is pulled together tightly enough for nuclei to fuse.

Build It trains answer structure

Assemble a full-mark answer from its marking points, in the order an examiner wants them.

Moon means a natural body orbiting a planet.

TrueFalse

Test It catches misconceptions

Spot the fault in a statement. The traps are the mistakes students actually make.

721941163128510

Brain Breaks between sessions

Short focus games to reset attention, so the next set lands better than the last.

Every question in Waves, on a schedule.

Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.

Start revising, £5 a month See how the method works

Or £46 a year, about £3.83 a month. Cancel anytime.