Visible Light And The Solar System Flashcards
What is the geocentric model
A model of the solar system in which everything orbits the earth
What is a heliocentric model
A model of the solar system where everything orbits the sun
How did Galileo realise the heliocentric model was true
Using an early telescope, he discovered Jupiter had moons by tracking there paths, this showed that not everything orbited the earth
What is refraction
The change of speed and direction of a wave when it enters a new material
What is the interface in refraction
The point where refraction occurs, the boundary between two materials
What is the normal
A perpendicular line to the interface
What is the incident ray
The ray that enters the new medium
What is the refracted ray
The ray after the incidence ray has refracted
What is the ange of incidence and angle of refraction
Angle of incidence is the angle the incidence ray entered to the normal
Angle of refraction is ange the refracted ray is to the normal
What is a converging/convex lense
A lens that is curved outwards on both sides so it become thicker the closer to the middle
Wat are the properties of a convex lens
Refracts light inwards, the thicker it is, the greater the angle of refraction and the closer the focal point
What is the focal point
The point in which refracted light rays meet
What is the focal length and how can it be found
The length between the lens and the focal point, can be found by focussing the image onto a piece of paper and measuring the distance between the paper and the lens
How does a refracting telescope work
Light enter the objective ( a convex lens) lens that’s in a tube, this refracts the light and an eyepiece lens the magnifies the image
What is the difference between a real and virtual image
A real image. The rays actually meet where the image is seen, it can be put onto a screen such as paper
A virtual image, the rays appear to come from the image but don’t, it can’t be shown on a screen. E.g. Mirrors make virtual images
What are the problems with refracting telescopes
They need to be very long for a good magnification
If the lens insnt perfect, the colours wont be correct, it’s hard to make a large lens perfect
As some light is always reflected as well as refracted on the boundary, it’s hard for them to magnify faint images such as distant stars
How does a reflecting telescope work
Light enters the tube and reflects of a curved primary mirror, this focuses the parallel rays towards the secondary mirror, this reflects the light into the magnifying eyepiece
What are transverse waves
Waves in which movement of wave is perpendicular to movement of energy. S waves and electromagnetic waves are transverse
What are longitudinal waves,
Waves that travel in pulses such as sound and look like this
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What is frequency and its unit and formula
Amount of waves per second, measured in Hz hertz. Formula is
Amount of waves divided by time in seconds
What is wavelength
Length of one wave, distance between two crests or two troughs
What is amplitude
Furthest distance from middle of wave, crest to the middle
Wave length formulas
Distance(M)/time(S)
Frequency(Hz)*wavelength(M)
