Quick AQA GCSE P1 revision

1. [Everything You Need To Know]

2. All objects emit and absorb infrared radiation Hotter object = more infrared radiation emitted
Dark, matt surfaces = better emitters + absorbers of
infrared radiation
Light, shiny surfaces = poor emitters + absorbers + Good
reflectors
50 oC 100 oC

3. - The particles of solids, liquids and gases have
different amounts of energy.
- Solid = Strong forces of attraction, particles close
together, fixed regular arrangement, vibrate with
neighbouring particles in fixed position.
- Liquid = Weak force of attraction, particles close
together(can move past each other), irregular
arrangement, move randomly + slowly
- Gas = No forces of attraction, particles have more
energy than solid + liquid, free to move, move
randomly + quickly.
- Transfer of energy by: conduction,
convection, evaporation and
condensation all involves particles
- Condensation = losing kinetic energy,
particles closer together, gas - liquid, water
vapour in air becomes liquid when is
contact with a cold surface.
- Evaporation = particles escape liquid,
particles can evaporate below water’s
boiling point, particles near surface break
force of attraction and become gas, hotter
particles escape, leaving the liquid at a
lower temperature.
- Rate of transfer = surface area & volume,
material, colour.
- The larger the temperature difference to
quicker the rate of heat transfer.
This can come up as 6 marker!

4. - Specific heat capacity = J/Kg°C
- E = m x c x θ
- E is energy transferred in joules (J)
- m is mass in kilograms (kg)
- θ is temperature change in degrees Celsius, (°C)
- c is specific heat capacity in J / kg °C
- Water may be stored in solar panels so it may be used for domestic hot
water.
- The lower the U-value, the better the material is as an insulator.- U-values measure how effective a material is as an insulator.

5. 1.
3.
2.
4.
1. how effective a material is as an insulator
2. (the U-value) decreases
3. 4200, allow 2 marks for correct substitution ie 6930 = 0.330 x c x 5.0
answers of 1050 or 840 (3 marks), 1 mark for units ( j/kg oC)
4. (air) particles spread out (which causes the) air to become less
dense/
expand (so the) warm air rises

6. - Energy can be transferred usefully, stored, or
dissipated, but cannot be created or destroyed.
- When energy is transferred only part of it may be
usefully transferred, the rest is ‘wasted’
- Wasted energy is eventually transferred to the
surroundings, as thermal energy, (surroundings become
warmer. Spreads out and becomes less useful.
- To calculate the efficiency of a device use:
- efficiency = useful energy out
total energy in X (100%)
- efficiency = useful power out
total power in X (100%)

7. Leaf blower
3.
1.
2.
1. warms it
1. 37.5% or 0.375
1. 5.88 (watts)

8. N - Nuclear
E - Electrical (mains)
G - Gravitational Potential(pen on table
L - Light (bulb)
E - Elastic Potential ( spring)
C - Chemical (batteries)
T - Thermal (fire)
S - Sound (speakers)
---
K - Kinetic
- E = P x t == Energy transfer from mains
E = Joules (energy)
P = Watts (power)
T = seconds (time)
- To calculate the cost of mains electricity given the
cost per kilowatt-hour.
- E.g Electricity = 15p per Kwh
Power = 5000watts per hour from kettle
Runs for 30 mins
Cost?
5000watts = 5Kwh
5Kw x 0.5hr (30 mins) = 2.5Kwh
2.5Kwh x 15p = 37.5p
- Payback time = cost / saving per year(or month
depending)

9. 1. Chemical, kinetic, sound
2.
Examples of relevant statements:
• energy efficient boiler saves the most (energy / money) per year
• loft insulation costs the least to install
• double-glazing costs the most to install
Examples of statements that include cost effectiveness
• loft insulation is the most cost effective in the long term
• double-glazing is the least cost effective
• loft insulation has the shortest payback time
• double-glazing has the longest payback time
• payback time calculated for any method
Examples of further detail
• for cost effectiveness install in the following order: loft, cavity wall,
boiler, double-glazing
• for reducing energy use install in the following order: boiler, loft,
cavity wall, double glazing
• don’t install double-glazing for insulation purposes
• double-glazing won’t pay for itself in your lifetime
• justified choice of best / worst method

10. - Power stations need an energy source to heat up water, these
are the ones you need to know:
- Burning fossil fuels heats water
- Uranium and plutonium, when energy from nuclear fission
heats water
- Burning biofuels heats water
- Water and wind can be used to rotate turbines
- Electricity can be generated directly from sunlight
- Geothermal energy is when steam from volcanic areas is used
to turn turbines
- Hydroelectricity in remote areas(country-side) and solar cells for
roadside signs
- Generating electricity has some effects:
- The release of substances into the atmosphere
- The production of waste materials
- Noise and visual pollution
- The destruction of wildlife habitats.
- Electricity is distributed from power stations to
consumers (us) along the National Grid.
- Step-up transformer Increases voltage and decreases
Current, this reduces energy loss(as thermal energy)
which makes it more efficient.
This can come up as 6 marker!

11. Why is a Step-up transformer used in the
national grid?
[3 marks]
1.
5.
2.
3.
4.
1. (heated) water turns to steam, steam turns
a turbine, turbine turns a generator
1. advantage any one from:
• produce no / little greenhouse gases / carbon
dioxide
• high(er) energy density in fuel
• long(er) operating life
disadvantage any one from:
• produce (long term) radioactive waste
• accidents at nuclear power stations may have far
reaching or long term consequences
• high(er) decommissioning costs
• long(er) startup time
3. any one from:
• cannot be seen
• no hazard to (low flying) aircraft / helicopters
• unlikely to be or not damaged / affected by
(severe) weather
• (normally) no / reduced shock hazard
4. They rely on the wind
5. Increases voltage
Decreases current
Reduce power loss(heat)
Increase efficiency

12. - Waves transfer energy
- Waves may be either transverse or longitudinal.
- Electromagnetic waves are transverse, sound
waves are longitudinal and mechanical waves may
be either transverse or longitudinal
- All types of electromagnetic waves
travel at the same speed through a
vacuum (space).
- Electromagnetic waves make up a
continuous spectrum
- Longitudinal waves show areas of
compression and rarefaction.

13. - Waves can be reflected, refracted and diffracted (Learn the
names of the angles below or look next slide)
- Waves undergo a change of direction when they are
refracted at an interface
- You must know the terms frequency, wavelength and
amplitude
- All waves obey the wave equation:
V = f x λ
v = speed in metres per second, m/s
f = frequency in hertz, Hz
λ = wavelength in metres, m
- Radio waves, microwaves, infrared
and visible light can be used for
communication.

14. - The normal is a construction line
perpendicular to the reflecting surface
at the point of incidence.
- The angle of incidence = the angle of
reflection.
- The image produced in a plane mirror
is virtual and upright
- Sound waves are longitudinal waves
and cause vibrations in a medium,
which are detected as sound.
- The pitch of a sound is determined by
its frequency and loudness by its
amplitude
- Echoes are reflections of sounds.

15. - If a wave (e.g light) is moving away
from you, the observed wavelength
increases and frequency decreases.
- If a wave (e.g light) is moving towards
you, the observed wavelength
decreases and frequency increase
- This is known as the Doppler effect
- Observed wavelength (of light) are increases from distant
galaxies, the further away the galaxies are the faster they
are moving and a bigger increase in wavelength- Red-Shift.
- Red-shift shows all galaxies are moving away from us, this
supports the big bang as everything must have started at 1
point.
- Cosmic microwave background radiation (CMBR) is
radiation from the beginning of the universe.
- The ‘Big Bang’ theory is currently the only theory that can
explain the existence of CMBR.

16. 5.
1.
2.
3.
4.
1. Microwave
4. Doppler effect
1. Refraction
1. any two from: • transverse
• same speed (through air)
• can be reflected
• can be refracted
• can be diffracted ... more
5. 0.773 (metres)
allow 1 mark for correct substitution ie 340 = 440 ×
λ
allow 2 marks for an answer that rounds to 0.773

17. 1. A vacuum flask is designed to reduce the rate of energy transfer by heating process. Describe how the design of a vacuum flask keeps the
liquid inside hot?
2. A car engine that overheats can be damaged or even catch fire. Therefore a cooling system transfers energy from the engine to a radiator. The
energy in the radiator is transferred to the air. Explain the factors that affect the rate of energy transfer in the engine and radiator.
3. Home heating bills can be very expensive. Describe the different methods by which we can reduce the rate of energy transfer at home and
reduce the home heating bills.
4. Compare the similarities and differences between the process of conduction in metals and nonmetals.
5. Explain why an electric heater is the only appliance that can possibly be 100% efficient.
6. Compare the advantages and disadvantages of buying compact fluorescent bulbs rather than filament bulbs
7. Advantages and disadvantages of the different methods of energy production
8. Power stations that burn fossil fuels produce waste gases that can cause pollution. Describe the effect that these gases could have on the
environment and what could be done to reduce the amount of these gases emitted by power stations.
9. What are the advantages and disadvantages of using solar energy to heat water in a tank rather than using an electric immersion heater?
10. Advantages and disadvantages of overhead and underground cables.

18. 11. Compare the advantages and disadvantages of overhead power lines and underground cables in the transport of electrical energy around the country
12. The diagram shows an oscilloscope trace of the sound wave produced by a musical instrument.
Explain, in detail, how the waveform would change if the instrument produced a sound which was louder and at a higher pitch
13. One theory suggests the universe began with the Big Bang. Explain what is meant by the Big Bang and describe the evidence that supports this theory
14. Explain how red-shift provides evidence for the Big Bang theory.