Visible Light and the Solar System Flashcards
Define heliocentric
Sun centred
Sun centre of Solar System, planets orbiting
Define geocentric
Earth centred
Earth centre of Solar System, planets & sun orbiting
How do scientists use waves to find out information about the universe?
Visible light waves - study distant objects (telescope, naked eye, photography)
Radio waves & microwaves - detect objects that do not give out visible light (different types of telescopes)
How did Galileo’s observations of Jupiter using the telescope provide evidence for the heliocentric model of the solar system?
By plotting movement of moons around Jupiter, showed that not everything orbited Earth.
Explain how to measure focal length of converging lens using a distant object.
Distance between focus & lens - focal length of that lens
Focal length can be found by focusing image of distant object onto paper
How does the eyepiece of a simple telescope magnify the image of a distant object produced by the objective lens?
Convex (objective) lens creates an image inside the tube and eyepiece lens magnifies image
How are waves refracted?
At boundaries between different materials
How are waves refracted at boundaries?
Occurs because light travels at different speeds in different materials. Part of wave hits boundary first so slows down first, wave refracts.
Air –> glass: slows down, refracts towards normal.
How are waves reflected?
At boundaries between different materials waves are reflected.
How does a reflecting telescope work?
Light enters telescope at parallel angles & hits concave primary mirror which focuses image. Reflects off at angle and goes in a straight line at secondary mirror. Light rays reflected towards eyepiece lens, which magnifies image.
What do waves transfer?
Energy and information, without transferring matter
Define frequency (waves)
The number of waves passing a point each second (Hz)
Define wavelength
The distance between a point on one wave and the same point on the next (m)
Define amplitude
The maximum distance of particles in a wave from their normal positions
Define speed
Distance a wave travels in one second (m/s)
What is a longitudinal wave?
Waves in which particles move back and forth in parallel with the direction of movement of the energy. The direction of energy transfer is parallel to the direction of the vibration which causes them.
What is a transverse wave?
Waves in which movements are at right angles to the direction of movements of energy (electromagnetic waves)
What is the equation for wave speed?
Distance/time, frequency x wavelength
