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P5

Anna Hollywood Physics GCSE English 4.8Average rating 4.8 out of 5 (5 ratings) 110 cards

P5

Cards in this deck (110)

  1. 1When are the forces of gravity only noticeable?On an astronomical scale
  2. 2Why do planets stay in orbit around the sun?Because of gravitational attraction
  3. 3What is the force applied to the centre of an orbit?The centripetal force
  4. 4The larger the mass the greater/weaker the gravitational force?Greater
  5. 5The further away an object is the smaller/greater the gravitational forceSmaller
  6. 6Force is indirectly proportional to...1
    -------------
    distance squared
  7. 7Why is the orbit time for a planet closer to the sun less?Shorter distance...faster (greater gravity)
  8. 8How does a satellite orbit the earth?At a tangent and gravity makes it accelerate towards the earth
  9. 9Whereabouts do polar satellites orbit?20-100km above the north and south poles
  10. 10How long do polar satellites take to orbit the earth?About 90 minutes
  11. 11How much of the earth's can polar satellites see?All of it
  12. 12What are polar satellites used for?Imaging the earth-including short range weather forecasting
  13. 13Whereabouts do geostationary satellites orbit?Above the equator
  14. 14How long do geostationary satellites Take to orbit?24 hours
  15. 15What are geostationary satellites used for?Communication
  16. 16How do you calculate the distance travelled by a satellite?2 x (pi) x radius (from centre of earth)
  17. 17All geostationary satellites must be in different/the same orbitThe same
  18. 18Why can't geostationary satellites be too close together?As their signals would overlap due to diffraction
  19. 19What is a scalar quantity?Only magnitude (e.g. speed)
  20. 20What is a vector quantity?Magnitude and direction (e.g. velocity)
  21. 21What are vectors normally represented by?Arrows
  22. 22What is 3m/s to the right + 2m/s to the left?1m/s to the right
  23. 23How is the resultant of two forces that are not in the same direction found?By using Pythagoras (to find size) and trigonometry to find the angle
  24. 24What does U stand for in equations of motion?Initial velocity
  25. 25What does V stand for in equations of motion?Final velocity
  26. 26What does A stand for in equations of motion?Acceleration
  27. 27What does S stand for in equations of motion?Distance travelled
  28. 28What does T stand for in equations of motion?Time taken
  29. 29What is the acceleration of an object thrown into the air?-10m/s(squared)
  30. 30What is the velocity of a ball at the top of its ascent?0
  31. 31A ball thrown horizontally from the top of a tower will fall at the same rate as a ball dropped from the top of a tower. True or false?True
  32. 32What is the trajectory of a ball thrown horizontally?Parabolic/A parabola
  33. 33What equation do we use to work out the horizontal motion of a ball?distance = speed x time
  34. 34What type of horizontal velocity does a ball have (been thrown from tower)?Constant
  35. 35What is the resultant velocity?The vector sum of the constant horizontal velocity and the vertical velocity
  36. 36What do forces always occur in?Pairs
  37. 37The action and reaction pairs of forces are... (3 things)equal in size...opposite in direction...act on different objects
  38. 38What law is it that states that forces come in pairs?Newton's third law
  39. 39Why do we have weight?Because we are attracted to Earth due to gravity
  40. 40What is the opposite force to us being attracted to Earth?Earth being attracted to us
  41. 41Why does a gun recoil after a bullet is shot out of it?Because the bullet exerts the same amount of force onto the gun than the gun does to the bullet
  42. 42What is the opposite of an explosion? What is still conserved?A collision. Momentum
  43. 43How does pressure build up in a gas container?The particles of the gas collide with the walls of the container, creating a force (and hence a pressure) on the walls
  44. 44How does a larger volume increase pressure?Particles collide with walls of container more often, more energy, more pressure
  45. 45How does increasing the temperature increase pressure?Particles move faster...hit walls more often...with greater force...increasing pressure
  46. 46Force = rate of change of (what?)momentum
  47. 47As a rocket moves up, the hot gases released move ......... . Momentum is ................ . This means that the high momentum of the large massed rocket moving up is ............... by the high velocity of the exhaust gases.As a rocket moves up, the hot gases released move DOWN. Momentum is CONSERVED. This means that the high momentum of the large massed rocket moving up is BALANCED by the high velocity of the exhaust gases.
  48. 48What are microwaves sent into space by?A parabolic transmitter
  49. 49What satellites are used to receive, amplify and re-transmit the microwaves back to earth?Geostationary satellites
  50. 50When microwaves return to earth, what are they received by?Parabolic receiver
  51. 51Why are digital signals used for satellite communication?They do not attenuate as quickly and there is less noise
  52. 52What frequencies of radio waves does the ionosphere reflect?Below 30 MHz
  53. 53What happens when radio waves with frequencies above 30 MHz meet the ionosphere?They get absorbed and scattered, reducing signal strength
  54. 54What range of frequencies are used for satellite communication?Between 3GHz and 30GHZ
  55. 55How high above the earth do geostationary satellites orbit?36,000km
  56. 56Why is the size of a geostationary satellite's dish many times bigger than the microwaves wavelength?So their is very little diffraction and this produces a narrow beam that doesn't spread out
  57. 57Why do the receiving dish and transmitting dish need exact alignment?To ensure the signal hits the geostationary satellite
  58. 58What do microwaves do as they are fired into space?Pass through the Earth's atmosphere and (as they have a very small wavelength) don't spread out much
  59. 59What is the ionosphere?A region between 100km and 500km above the Earth
  60. 60What do radio waves undergo as they enter space?A series of refractions and they speed up as they go, eventually undergoing total internal reflection
  61. 61The smaller the size of a gap the greater/lesser the diffractionGreater
  62. 62Which of these diffracts more.... radio waves or TV signals?Radio waves (TV signals transmitter and receiver MUST be in line of sight)
  63. 63When does maximum diffraction occur?When the wavelength is equal to the size of the gap
  64. 64Why would radio waves diffract in a hilly area?As they have long wavelengths compared to the distance between hills
  65. 65What will happen if you place two speakers (connected to the same output) and place them about 1 metre apart?You will hear alternate loud and quiet areas as you move along a line in front of them
  66. 66What does it mean when two crests/troughs overlap?The waves are in step and the sound will be loud
  67. 67What does it mean when a trough and a crest overlap?The waves are out of step and the sound will be quiet
  68. 68What is constructive interference?The waves meet in phase
  69. 69What is destructive interference?Waves meet out of phase
  70. 70Show the diagram for constructive interferenceShow the diagram for constructive interference
  71. 71Show the diagram for destructive interferenceShow the diagram for destructive interference
  72. 72In terms of half wavelengths, when does constructive interference occur?When there are an equal number of half wavelengths
  73. 73In terms of half wavelengths, when does destructive interference occur?When thee are an odd number of half wavelengths
  74. 74Generally, when does interference between light waves occur?When light diffracts as it passes through narrow slits
  75. 75What kind of interference is light bands and what kind of interference is dark bands?Light - constructive
    Dark - destructive
  76. 76Why do the slits have to be closer together than the speakers?Because light wavelengths are shorter than sound wavelengths
  77. 77What kind of waves are electromagnetic waves?Transverse waves
  78. 78When is light polarised?If the oscillations are only in one direction at right angles to the wave direction
  79. 79How do polaroid sunglasses work?They stop oscillations in all but one direction at right angles to the wave, reducing the amount of light that passes through
  80. 80What did Newton think of light as and why was he wrong?As a particle and if this was true then light would travel faster in a denser medium
  81. 81What did Huygens think of light as?A wave
  82. 82Why does refraction occur?Because when light enters a different medium, it changes speed
  83. 83What does light do as it enters a more dense medium and why?It slows down - it deviates towards the normal
  84. 84What does light do as it enters a less dense medium and why?It speeds up - it deviates away from the normal
  85. 85What is the refractive index?A number that is the ratio of the two speeds of the speed of light between air and a medium
  86. 86What is the equation for working the refractive index?RI (n) = speed of light in vacuum
    ----------------------------
    speed of light in medium
  87. 87Why does dispersion occur?Because each colour slows down by a different amount when white light enters a medium and speeds up by different amount when leaving
  88. 88What does Snell's law state?RI (n) = sin incidence
    ---------------
    sin refraction
  89. 89When light passes from a more dense medium into a less dense medium the angle of refraction is ................ than the angle of incidenceLarger
  90. 90What is the critical angle?The angle of incidence in the more dense medium that produces an angle of refraction of 90 degrees in the less dense medium
  91. 91What happens if the critical angle is exceeded?The light is totally internally reflected
  92. 92What do optical fibres rely on?Total internal reflection
  93. 93What three things are optical fibres used for?-Carrying telephone conversations
    -Carrying computer data
    -For endoscopes
  94. 94The higher the refractive index of a material, the higher/lower its critical angleLower
  95. 95n = 1 ---- ?sin c
  96. 96A parallel beam of light from a distant object can be .................... to a focus in the ........... planeconverged, focal
  97. 97What happens if the beam is parallel to the principal axis?The light is focused to the focal point on the principal axis
  98. 98What will a diverging beam from a near object do?It will focus at a point beyond the focal plane
  99. 99How does a camera work?Light passes through lens...focused on film...size of image is smaller than object
  100. 100How is a projector different to a camera?Same thing happens but the film is closer to lens and so image is bigger than object
  101. 101What can we do to find the position and size of an image created by a convex lens?Use a scale diagram
  102. 102What happens to the top ray?Refracted through focal point of convex lens
  103. 103What happens to lower ray?No deviation, goes straight through
  104. 104What are the two properties of an image formed by a magnifying glass?Right way up and cannot be projected onto a screen
  105. 105What is the difference between simple and more advanced cameras?More advanced have sharper images at any distance as they have an adjustable lens
  106. 106What is the aperture?An adjustable hole allowing different amounts of light onto the film
  107. 107What do the condenser lenses do in a projector?Make sure the film is uniformly illuminated
  108. 108What does the curved mirror do in a projector?Reflects light back into the condenser lenses
  109. 109Magnification =image size
    ---------------
    object size
  110. 110Why can't the image produced by a magnifying glass be projected onto a screen?It is virtual - no light passes through it

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GCSE Physics (P5) Flashcards on P5, created by Anna Hollywood on 01/01/2014.
Created by
Anna Hollywood
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