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26 Cards in this Set
- Front
- Back
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Land based telescopes |
+Cheaper than space telescopes +Easy to repair/maintain +Collect all EM waves -some waves absorbed by atmosphere -atmoshpheric pollution -need a suitable location |
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Orbital telescopes |
+no atmospheric pollution +clear,close up images +receives all EM waves -repaired by astronauts -expensive -hard to update so it may become space junk |
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Space probes |
+unmanned(no life risk) +soil samples +works for years -expensive -unrecoverable if problems occur -wrong programming may lose it |
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Space shuttles |
+tech has helped with modern items +repairs fixed easily by crew +very clear images -risk to life -expensive -can only travel certain distance/time |
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Speed of light |
3x10(8)m/s |
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Speed of sound |
330m/s |
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Geocentric model |
Everything orbited the Earth Ptolemy |
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Heliocentric model |
Everything orbited the Sun. Only planets up to Saturn listed due to bad telescopes Copernicus |
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Improved heliocentric model |
Moons orbit planets and planets orbit the Sun. Galileo He observed one of Jupiter's moons. |
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Transverse waves |
Vibrations of waves travel at 90o to the direction of travel. Examples: EM waves and S waves |
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Longitudinal waves |
Vibrations of waves are along the same direction as the wave is travelling. Examples:sound and P waves |
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Reflection |
When a wave hits a boundary between one medium and another, some of the energy is reflected. Angle of reflection=angle of incidence |
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Refraction |
When a wave passes into a new medium of a different density, it's speed and direction change. If it travels through a denser medium, the wave slows and bends towards the normal. |
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Real image |
Light from an object comes together to form an image on a screen. |
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Virtual image |
Light rays from an object don't meet, so the image appears to be somewhere else. |
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Refracting telescope |
An object emits light which the objective lens picks up and converges. This produces a real image at the focal point. The image is then viewed through the eyepiece lens. |
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Reflecting telescope |
An object emits light which the objective lens collects. It then hits a concave mirror which reflects light onto a second mirror. This then converges the light to form an image at the eyepiece lens. |
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Herschel |
Measured the temperature of each colour in the visible light spectrum. He found it increased fro violet to red. He then measured past red and found it was hottest. This was infrared, |
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Ritter |
Knew silver chloride strips went from white to black when exposed to light.He timed how long it took this change to occur at each colour in the spectrum.The strips changed quickest near the blue end.He put one past violet and saw the quickest change. This was UV. |
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Radio waves |
Uses:they are used for communications and television signals. Dangers: linked to cancer |
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Microwaves |
Uses: heating food(cause water molecules to vibrate) and mobile phones Dangers: cataracts and linked to brain tumours |
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Infrared waves |
Makes molecules vibrate, heating them. Uses:TV remotes and thermal imaging Dangers:heats body and may cause burns |
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Visible light waves |
Uses: lamps and laser projectors Dangers:eye damage |
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UV waves |
Uses:tanning beds and detecting forged bank notes. Dangers:burns/skin cancer and eye damage Ionising, so it causes cell damage/mutation |
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X-ray waves |
Uses:X-rays and airport scanners Dangers:cancer and cell damage as they're ionising |
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Gamma waves |
Uses:food sterilisation and radiotherapy (to treat cancer) Dangers: may cause cancer as it's ionising and kills or mutates cells. |
