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78 Cards in this Set
- Front
- Back
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Natural Satellite |
A satellite that exist due to natural causes |
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Artificial Satellite |
Man made object orbiting around earth or other planets |
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Artificial Satellites Uses |
Telecommunication Weather Prediction Military Uses Satellite Navigation Systems Scientific Research Producing Images of the Earth |
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Inverse Square Law |
The force of gravity between two objects is inversely proportional to the distance between the two |
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Elliptical Comet Orbits |
Distance from the sun and speed of orbit varies Gravitational force is greater closer to the sun; the comet moves faster |
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Trajectory of a Satellite |
The path of orbit a satellite takes |
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Low Polar Orbit |
An orbit that goes over the north and south poles of the earth |
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Geostationary Orbit |
The Satellite orbits at the same speed that the earth rotates Orbits the earth once every 24 hours Remains in a fixed position over the Earth Orbits above the equator |
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Uses of Polar Orbits |
Taking pictures of the Earth's surface Military purposes |
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Uses of Geostationary Orbits |
Communications TV Broadcasts Weather Prediction |
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Centripetal Force |
Force acting on an object that allows it to follow a circular path, acting towards the centre of the circle Move at right angles from the centre to form its circular motion with its high velocity maintaining movement |
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Scalar Quantity |
A quantity that only has size |
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Vector Quantity |
A quantity with size and direction |
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Resultant Velocity |
Sum of Horizontal and Vertical Velocity's |
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SUVAT S |
Average Speed |
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SUVAT U |
Initial Speed |
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SUVAT V |
Final Speed |
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SUVAT A |
Acceleration |
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SUVAT T |
Time |
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Projectile |
An object thrown through the air in a curved path |
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Parabolic |
The curved shape of the path a projectile takes |
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Optimum Angle |
The launch angle that gives the largest projectile range |
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Action and Reaction with the Earth |
An object on the earth's is exerting an action force on the earth through it's weight pulled by the earth The reacting force is the earth pulled by the object |
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Collisions of Two Forces |
Equal force is exerted from each object- a car and a post |
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Recoil |
Backwards movement of an object by a force exerted on it |
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Burning Rocket Fuels in a Combustion Chamber |
Particles crash into the sides of the chamber, speeding up as the chamber gets hotter under high pressure. The momentum of the collisions change, causing enough of a force to lift the rocket of the ground. |
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Law of Conservationn of Momentum |
Total Momentum before collision = Total Momentum after Collision |
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Conservation of Momentum in Guns |
The gun and the bullet, when the gun is fired, have an equal momentum. The mass of the gun causes the velocity of it to be much greater than the bullets. |
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m1u2 + m2u2 = (m1 + m2)v M, U and V stand for.... |
Mass Velocity before the collision Velocity after the collision |
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Microwaves and TV Aerials |
Microwaves travel at the speed of light from a local transmitter and are received by the TV Aerial |
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Satellite TV |
Signal is beamed down from a satellite in orbit Higher frequency wavelengths are used |
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Signals from satellites are ________. This allows them to be processed by computers to remove _________. Satellites can pass signals around the world. One satellite ______ the signal before transmitting it to another ________. |
Digital Interference Processes Receiver/Satellite |
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Microwaves Wavelength |
Shorter wavelengths than radio waves, so don't spread out or diffract as much. Large receiving dishes need careful alignment to ensure the microwaves reach the receiver. |
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Ionosphere |
Layer of ionised particles in the upper atmosphere of the earth |
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The Ionosphere and Electromagnetic Waves |
Radio Waves and Microwaves are reflected back from the ionosphere, disrupting with communications. Only shorter wavelengths can pass through the ionosphere, making it valuable to communications |
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Diffraction |
The spreading out of waves upon reaching an obstruction or gap to pass through |
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Stronger Refraction Occurs When.... |
The wavelength is wrong The gap is smaller |
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Constructive Interference |
When two waves are overlapping in step (forming Crests and Troughs simultaneously) and make an overall wave with a much greater amplitude. They are in phase. |
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Destructive Waves |
When overlapping waves aren't in step, cancelling each other out to leave no wave |
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Coherent Waves |
Waves with the same velocity and frequency |
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Monochromatic Light |
Light of a single frequency |
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Path Difference |
The difference between two wavelengths travelling different distances |
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Path Difference in Constructive and Destructive Interference |
Constructive has an even number of half wavelength path differences Destructive has an odd number of half wavelength path differences |
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Newton's Theory of Light |
He thought light was made from particles, explaining refraction and reflection in terms of particles |
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Light does not diffract unless a very ________ _______ is used as it has a _________ wavelength. |
Small gap/Slit Short |
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Interference in Light |
If light is diffracted with two slits, the waves form an interference pattern-something that particles don't do. Bright and dark bands from the two slits is formed from constructive or destructive interference because of a path difference. |
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Polarisation |
Limits the vibrations of transverse waves to one plane only-side to side or up and down |
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Polaroid Filter |
Only lets light through that is polarised to a single plane Eventually all the light can be blocked with two filters slow rotation in front of each other |
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Refraction |
The bending of light as it travels from one medium to another |
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Factors Affecting Refraction |
If the light enters a denser material (air to glass), it slows down, forcing it to bend towards the normal. If the light leaves a denser material than it speeds up, bending away from the normal.\ |
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Refractive Index |
Measure of how much a substance bends after a boundary |
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Refractive Index Equation |
Speed of Light in Vacumm / Speed of Light in Medium |
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Dispersion |
The splitting of white light into its component colours through refraction |
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Use of a Prism to Refact Light |
When light enters a prim it slows and refracts, bending towards the medium. Colours are refracted by different amounts, and is refracted again when it leaves the prism. This causes enough dispersion for different colours to be visible. |
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Frequency and Wavelength in the Visible Spectrum (Highest and Longest) |
Violet has the highest frequency Red has the longest wavelength |
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Refractive Index in Colours |
The shorter the wavelength, the higher the refractive index, so violet has the highest refractive index |
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If the Angle of Incidence is Below the Critical Angle..... |
Some refraction and reflection takes place |
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If the Angle of Incidence is at the Critical Angle..... |
Some reflection takes place |
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If the Angle of Incidence is Above the Critical Angle..... |
Total internal reflection takes place |
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Total Internal Reflection needs... |
The light to be travelling in the more dense material The angle of the light to be greater than the critical angle |
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The critical angle depends on.... |
Its refractive index, the higher the refractive index, the lower the critical angle |
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Optical Fibres |
A fine glass tube that allows light to travel through it using total internal reflection Can be used for communication and medicine by producing images within the body |
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Binoculars |
Contain a pair of prisms that are specially shaped so that light is totally internally reflected, creating a magnified image. |
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Cat's Eyes Lights on Main Roads |
Light from car headlights are totally internally reflected in the Cat's Eyes to return to where it came from, allowing drivers to see wide stretches of road. |
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Principal Axis |
Line through the centre of a lens at right angles to its planes |
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Focus |
Single point that rays are focused to in a lens |
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Focal Length |
Distance from the optical centre of the lens to the focus |
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Converging Lens |
A lens that changes the direction of light rays parallel to the prncipal axis to meet at the focus after passing through the lens |
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Diverging Lens |
Rays spread out from a focus before reaching the lens, travelling parallel to the principal axis after passing through it. |
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Light Passing through the Optical Centre... |
continues in a straight line |
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Light Travelling Parallel to the Principal Axis... |
is refracted by the lens so it meets the focus |
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Light that Passes through the Principal Focus... |
Is refracted by the lens to travel parallel to the principal axis |
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Uses of Convex Lenses |
Cameras Projectors Magnifying Glasses |
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Real Image |
An image that can be displayed on a screen Image is upside down |
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Virtual Image |
An image that cannot be displayed on a screen Image is the right way up |
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Images Created of Further Away Objects |
Uses a convex lens Smaller image than the object Real Image
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Magnification Equation |
Image Height / Object Height |
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Convex Lens in Magnifying Glasses |
Light passing through the lens is refracted in a way that lets it create a larger image |
