# Physics 1 edexcel topic 1 gcse

gcse revision mind map on visible light solar system waves and reflection

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• Created by: Chloe
• Created on: 06-03-13 10:55
• Topic 1
• Solar System
• Ancient Greeks- Geocentric Model: all orbits Earth
• Copernicus 1543 introduced Heliocentric Model: all orbits Sun
• 1610, Galileo observed Jupiters moons and saw they orbitted Jupiter so proved not everything orbitted Earth and that the Geocantric Model was wrong.
• Current model shows that the planets in our solar system orbit the sun but the orbits are elliptical and nnot circular.
• As technology improves so does our understandingof the Universe eg the invention of the telescope led to the discovery of Uranus
• Visible Light
• Luminous objects in space give out visible light which travels as waves of energy.
• Most of the stuff that astronomers and scientists have learnt has been by using the naked eye.
• Most  objects in space are so far away that using the naked eye is only good for  mapping their positions.
• Telescopes magnify images so distant objects can be seen in more detail.
• Telescopes have problems eg light pollution, space telescopes overcome those issues but they are expensive.
• Waves
• Wavelength is the distance from one peak to the next.
• frequency is how many complete waves there are per second: 1 Hz is 1 wave per second.
• Amplitude is the height of the wave.
• Speed is how fast it goes
• waves transfer  energy and information- they don't actually transfer matter
• Speed = frequency x wavelength
• m/s = Hz x m
• wave speed = distance    time
• Transverse- vibrate at a 90 degree angle to the direction of travel
• light and all EM waves
• S- waves (earthquakes)
• waves on strings and springs
• ripples on water
• Longitudal- vibrate along the same direction as the wave is travelling.
• sound and ultrasound
• P- waves (earthquakes)
• slinky spring when you push and pull the end
• oscilloscopes always show things as transverse waves even sound.
• Reflection and Refraction
• reflection
• when a wave hits a boundary between one medium and another some of its energy is reflected.
• why you can see your reflection in a puddle
• the light is reflected due to a change in density. a different density causes light to be reflected at the boundary.
• this is what happens in ultrascanning