Physics Unit 1 Aqa Gcse

Front 1

infared radiation

Back 1

all objects emit it, makes us feel warm, can travel through a vacuum, (energy from the sun through space) it is a transfer of electromagnetic waves

Front 2

surfaces

Back 2

dark, matt surfaces: good absorbers and emiiters of infared radiation
shiny, light surfaces: good reflectors of infared radiation

Front 3

conduction

Back 3

If one end of a solid is heated, the particles gain kinetic energy and vibrate more passing it on, Free electrons gain the energy as well, colliding with other particles to pass on the energy

Front 4

insulators

Back 4

contain trapped air

Front 5

convection currents

Back 5

when the fluid is heated it expands, thus becoming less dense and rises. It is replaced with denser, cooler fluid, this causes the convection currents which transfer energy through the fluid

Front 6

Evaporation

Back 6

the most energetic molecules escape from the liquids surface into the air thus meaning the average kinetic energy is less so the temp decreases

Front 7

what increases evaporation

Back 7

-increasing SA
-increasing temperature
-creating a draught of air across the liquids aurface

Front 8

rate energy tansferred depends on:

Back 8

-material the object is in contact with
-object's shape
-objects SA

Front 9

Houses, minimising heat transfer

Back 9

-Loft insulation, reduce energy transfer by conduction
-Cavity wall Insulation traps air in small pockets to reduce energy transfer by convection
-Double glazing, reduces heat loss by conduction through windows

Front 10

Continued housong energy loss

Back 10

-Draught proofing reducing energy transfer by convection
-Aluminium foil behind radiatios to reflect infared radiation back into the room

Front 11

U-value?

Back 11

Tells us how much energy per second passes through jt

Front 12

Types of energy

Back 12

Light, sound, kinetic, nuclear, electrical, GPE, elastic potential and chemical

Front 13

Falling objects

Back 13

turn GPE into kinectic

Front 14

Conservation of energy

Back 14

Total amount of energy is always the same, cant be stopped only transferred

Front 15

Sankey diagram

Back 15

Front 16

Energy from wind and water

Back 16

Wind- to drive turbines
water- falling water, HEP or waves and tides

Front 17

Power from the sun

Back 17

Solar energy is transferred into electrical energy by a solar cell

Front 18

Geothermal energy

Back 18

Front 19

National grid

Back 19

Uses step-up and step-down transformers because they reduce energy wasted in cables, more efficient

Front 20

nature of waves

Back 20

Transverse: Oscillatiom of the particles is perpendicular to the direction of the wave
Longitudinal: Oscillation of the particles is parallel to the direction of the wave, has compressions and rarefractions

Front 21

types of waves

Back 21

-Electromagnetic waves can travel through a vacuum E.G. light or radio
waves which are transverse
-Mechanical waves travel through
medium substances (can be both types e.g. waves on a spring)
-Sound waves are both

Front 22

Measuring waves

Back 22

also frequency is number of compressions per second

Front 23

Law of reflection

Back 23

Front 24

Image formation by a mirror

Back 24

Front 25

the image in a planr mirror is

Back 25

-same size
-upright
-same distance between mirror
-virtual

Front 26

refraction of light

Back 26

Front 27

refraction continued

Back 27

When light enters a:
-more dense substance like glass it slows down and the ray bends towards the normal
-less dense substance like air it speeds up and the ray bends towards the normal

Front 28

different colour rays

Back 28

refract differently due to different wavelengths, violet light refracts the most and red light the least

Front 29

waves

Back 29

Front 30

electromagnetic spectrum

Back 30

Front 31

light

Back 31

-white light contains all the colours of the spectrum
-visible light, infared radiation, radio and microwaves all used for communication
ROYGBIV

Front 32

optical fibres

Back 32

very thin fibres used to transmit signals by light and infared radiation

Front 33

Doppler effect

Back 33

an increase in the frequency of wave e.g. sound as the observer moves towards the source then vice versa away from the source

Front 34

Red-Shift

Back 34

galaxies moving away from us give off light that bends towards the red end of the spectrum, every galaxy is moving away thus meaning the universe is expanding

Front 35

Blue-shift

Back 35

indicates a galaxy is moving towards us. We observe this by seeing dark lines in the spectra from the galaxies

Front 36

Big bang proof

Back 36

scientists discovered microwaves coming from every direction in soace, cosmic microwave background radiation prpduced by the Big Bang (the only thing proving CMBR)