Winter Arc Flashcards
What is the stages of the Big Bang Theory
- Big Bang occurred 14 billion years ago from one point known as singularity
- Universe made up of high energy radiation and quarks
- rapid expansion and cooling
- Quarks come together to form protons and neutrons
- Further expansion and cooling allowed nuclei to form
- after further expansion and cooling temp fails sufficiently to enable electrons to form
7.Electronscombined with neutrons and protons to form atoms of hydrogen
Life cycle of star if its similar to Sun
Protostar —>Main Sequence Star —> Red Giant —> White Dwarf —> Black Dwarf
Life cycle of star if its larger than star
Protostar —>Main Sequence Star —> Red Supergiant —> Supernova —> Black hole OR Neutron Star
What do waves do
Transfer energy from one point to another through vibrations
Whats a Transverse wave
Particles of the medium vibrate at 90 degrees to the direction of wave travel(energy flow)
Example of Transverse waves
EM waves, Water Waves
Whats a longitudinal wave
Particles of the medium parallel vibrate to the direction of wave travel (energy flow)
Example of longitudinal wave
sound and ultrasound
What are the three wave properties
Amplitude
Wavelength
Frequency
What is Amplitude
Maximum displacement of the wave from its undisturbed position
What is Wavelength
Distance between a point on wave and the next point which is in the same state of vibration
What is Frequency
Number of waves produced in 1 second (Hz)
F = No. of waves divided by time(in seconds)
What do displacement- Distance wave graphs give information about
Amplitude
Wavelength
What are the three wave equations
V = Fxλ
F = v divided by λ
λ =V divided by F
What do displacement- Time wave graphs give information about
Amplitude
Frequency
What do the three wave equation symbols stand for λ, V, F
λ= wave length
V= wave speed
F= Frequency
What is the properties of the electromagnetic spectrum
All transverse waves
All travel at the same speed in a vacuum
What is the uses and dangers of Radiowave
Uses: Communication and Radio Entertainment
Dangers: Large doses believed to be able to cause cancer , leukaemia and other disorders
What is the uses and dangers of Microwaves
Uses: Heating food, communication by sending information to and from satellites in space
Dangers: cause internal heating of body tissues and burns. the heat which is released can damage or kill healthy cells
What is the uses and dangers of Infrared
Uses: Infrared cameras, cooking in toasters and grills, TV remotes, optical fibres for communication
Dangers: Burns, infrared from sun cause sunburn, cells absorb too much infrared radiation the heating will damage or kill cells
What is the uses and dangers of Visible Light
Uses: seeing objects, used in optical fibres e.g. endoscopes to see into patients bodies
Dangers: very intense visible light can damage retina at back of eye
What is the uses and dangers of Ultraviolet
Uses: security coding of equipment, sunbeds
Dangers: Can cause skin cancer by ionising cells under skins surface
What is the uses and dangers of X-Rays
Uses: Looking at bones in body
Dangers: can cause cancer if absorbed by cells (ionisation can occur)
What is the uses and dangers of Gamma
Uses: Used to kill cancer cells, kill bacteria in food, sterilise surgical equipment
Dangers: Can cause cancer by damaging healthy cells if it is absorbed
What is the law of reflection
Angle of incidence = angle of reflection (for a plane mirror)
What is the properties of an image in a plane mirror
Virtual
Same size as object
Laterally inverted (left right swapped)
Same distance behind the mirror as the object is in front of it
What does Refraction mean
Bending of light as it passes from one material into another. This happens due to a change of speed.
What is the steps of the refraction practical
Trace around a glass block
Draw the normal
measure angles of incidence with protractor
shine ray of light along each angle of incidence
mark where the ray leaves the block
remove block and join where ray entered and left the block
Measure angle of refraction
repeat for 5 different angle of incidence
What is the conclusion of the refraction practical graph
all points lie on trend line meaning there is a relationship between angle of incidence and angle of refraction.
They are not proportional (graph isn’t a straight line)
If light is moving into an object fast what happens
The light bends away from the normal
If light is moving into an object slower what happens
Light bends towards normal
What materials does light go through and speed up?
Glass to Air
Water to Air
Glass to Water
What materials does light go through and slow down?
Air to Water
Water to Air
Glass to Water
What factor affects the amount of refraction
The change of speed
Larger change of speed, there will be more refraction
What is dispersion
When white light is passed through a glass prism it splits up into 7 different colours and the effect is called dispersion
What is the principal axis
Ray that enters lens on normal and isn’t refracted
what is the optical centre
centre point of lens which principle axis passes through
What is the principal focus
point at which rays meet
What is the focal length
Distance between optical centre and principal focus
What is a magnifying glass
Convex lens used to make object appear much larger than it actually is
What is Cosmic Microwave Background Radiation
Left over energy from big bang
What is redshift
sai jumped
doppler effect
As object moves away from us the sound or light waves emitted by objects are stretched out which moves them towards red end of electromagnetic spectrum where light has longer wavelength
