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89 Cards in this Set
- Front
- Back
Analogue Storage |
a record or a tape that suffers from noise and distortion, has a continuous signal |
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Digital Storage |
A CD and a DVD, no deterioration, has a discrete signal, made up of binary signals |
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CCD |
a microchip that can be used electronically to record an image |
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Quantum Efficiency |
the number of electrons out and the number of protons in, it measures how efficient a CCD is |
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Magnetification |
the image size on the CCD/actual image size in real world |
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Polarised Wave |
The electric field only oscillates in one direction
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Unpoliarised Wave |
The electric field oscillates in random directions |
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the Rayleigh Criterion |
Used when resolving images, specifically two objects where the minimum of one diffraction pattern falls on the maximum of the other. |
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A Standing Wave/Maxima and Minima |
Formed by constructive interference of wave and reflected wave. Maximum=interference is constructive, waves are in phase. Minima= interference is destructive, waves are completely out of phase |
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Diffraction of Light |
The spreading of light by an obstacle, for example a slit spreads light. |
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Optically Active Substance |
A substance is one that rotates the plane of polarisation of light that passes through it. |
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The Doppler Effect |
Come about because wave fronts from a moving source or incident on a moving observer appear to bunch together or spread apart depending on the type of motion involved. |
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Frequencys |
When the observer moves towards the source a higher frequency is observed, and when the observer moves away form the source a lower frequency is observed. |
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Resolution |
the separation limit between two objects being observed such that they are just discernable as two separate objects of just one blur. Limit=Rayleigh Criterion |
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Polarity of the light/Polarized light waves |
The direction of the electric field vector. Light waves strike a surface in a place of incidence that are perpendicular to that plane of incidence will be reflected off the surface. These reflected waves are polarized. |
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Polarizer/Analyzer |
Takes an input of natural light and transforms it into an output of polarized light/ Used as a reference polarizing axis to determine if the first polarizer is in fact a linear polarizer. |
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Ideal Gas |
Very small particles, collisions between molecules and container are elastic. Have no inter molecular forces. |
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Pressure |
The momentum change per unit time between the molecules and wall defines a force at the impact point of the wall. P=Force/Area, in Pascals |
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Thermodynamic System |
the conditions under which heat can be transformed into mechanical work with a set of objects. |
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Internal Energy |
the total kinetic energy of the all the molecules of a gas plus the potential energy associated with inter molecular forces between the molecules. |
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Work done on or by the gas |
will change the state of the gas. If the gas is compressed, then work is done on the gas. If the gas expands, then work is done by the gas. Work is calculated as the area under a pressure against volume graph. |
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Specific Heat Capacity |
Amount of energy required to raise the temperature of a unit mass of material by one degree Kelvin |
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Heat Capacity |
The product of a mass times specific heat capacity, C=mc |
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Specific Latent Heat |
The heat required to change a unit mass from a solid to a liquid or a liquid to a gas. |
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de Brogile hypothesis |
Since light gave the same characteristic as a particle, all particles can therefore act like light and can produce waves, applies to all particles. |
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Evidence for the quantization of nuclear energy levels |
Alpha particles have discrete values of kinetic energies and Gamma-ray photons have discrete energies, Beta particles are continuous |
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The Schrodigner Model |
The hydrogen atom has a probability of finding an electron in a small region of space by calculating the amplitude of the wave function squared. |
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The photoelectric effect |
When a light strikes a metallic surface, electrons may be emitted from the surface. |
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Einstein's Model |
As the intensity of the light increase, more photons are striking the surface, emitting a larger number of electrons and producing a greater photo-current. Energy of the electrons does not change |
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Work Function |
The minimum energy to free an electron/having the photo-electric effect happen of the surface. |
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Natural Radioactive Decay |
Nuclei spontaneously emit particles, becoming different nuclei in the process. The process of nuclear decay is not affected by physical or chemical changes. Alpha, beta, and gamma emissions. |
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Changes of State |
Isothermal= temperature doesn't change Isobaric= pressure doesn't change Isochoric= volume doesn't change Adiabatic=everything changes except for internal energy |
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Degraded Energy |
Energy that is transferred to the surroundings is no longer available to perform useful work. |
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Non-renewable resources |
Cheap and emits CO2 emissions, coal and oil. |
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Nuclear Energy |
Renewable, high energy density, difficult to dispose of |
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Albedo |
The ratio of reflected to incident solar energy over the entire planet. Affected by the amount of Solar energy reflected by surface, earth's albedo depends on the season and latitude. |
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Black-Body Radiation |
The radiation that is emitted by a perfect emitter. |
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Coefficient of volume expansion |
the fractional change in volume per degree change in temperature. |
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The Greenhouse Effect |
the trapping of the sun's warmth in a planet's lower atmosphere due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted form the planet's surface. The natural frequency of oscillation of CO2 in the infrared region. |
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The Ampere |
The force between two long parallel currents. If two wires are 1 meter apart, then 1 amp of current flowing= the force to be 2x10^-7 N/m |
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The Mass Spectrometer |
Particles have two different radii, two different masses, which means different elements, so isotopes were discovered. |
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Induced emf |
The voltage across a circuit and is caused by any change in the magnetic environment of a coil of wire. |
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Magnetic Flux |
The key to the process of using motion to create electric current. The quantity of the total flux is called the flux linkage. |
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Faraday's Law |
The induced emf is equal to the negative rate of change of the magnetic flux. |
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Lenz's Law |
Deduces the direction of the induced current in a closed loop due to a change in magnetic flux. The induced current will be in such a direction as to oppose the change in magnetic flux that created it. |
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Alternating Current Generator (AC) |
Relative motion between a coil and a magnet will produce an induced current in the coil. The coil is rotated through a magnetic field which generates the ac current. As the rate of rotation increases, the frequency does too. |
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Root Mean Square Voltage and Current |
The rms value of an alternating current (or voltage) is that value of the direct current (or voltage) that dissipates power in a resistor at the same rate. RMS=rating. |
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Transformer |
A device that takes advantage of electromagnetic induction, it requires an input of alternating current. |
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Average Velocity vs. Average Speed |
The rate at which an object changes position vs. rate of change of distance |
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Instantaneous vs. Average Velocity |
Instantaneous is the velocity as a certain point which the average velocity is the amount of distance/time |
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Inertia |
When the object is at rest or it is moving at a constant velocity. Property of matter that resists change in motion. |
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Newton's First Law |
An object as rest or an object in constant velocity will remain at rest or at a constant velocity unless acted upon by an unbalanced force. |
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Newton's Second Law |
The net force of an object is equal to the mass times the acceleration. |
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Newton's Third Law |
For every action force there is an equal and opposite reaction force. |
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What is true for an object to be in static or transitional equilibrium? |
The net force must be 0; the objects can either be at rest or it can be moving at a constant velocity, so no acceleration. |
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Newton's Law of Universal Gravitation |
Two point masses will always attract each other with a gravitational force that is directly proportional to the product of the masses and inversely proportional to the square of the distance separating their centers. |
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Gravitational Field Strength |
The force pet unit mass on a small mass placed at a point |
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Gravitational Potential |
The work done to move unit mass form infinity to the point. |
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Escape Speed |
The takeoff speed needed to reach a position of zero potential energy and kinetic energy. |
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Kepler's 1st Law |
orbits of the planets are elliptical with the sun at one focus. |
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Kepler's 2nd Law |
A line connecting the sun and a planet sweeps out equal areas in equal times. This means planets move faster when closer to the sun and slower when farther from the sun. |
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Kepler's 3rd Law |
The square of the orbital period of a planet (T^2) is proportional to the cube of the semi-major axis (R^3) of T period of 1 revolution. |
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Electric Field Strength |
The force per unit charge on a small positive test charge placed at a point in the field. |
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Electrical Current |
The rate of flow per unit charge per unit time given at a point. |
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Ohm's Law |
The Current will be directly proportional to the potential difference for a constant temperature. |
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A Voltmeter |
Measures potential difference, should be connected in a parallel circuit and needs a high internal resistance. |
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An Ammeter |
Measures current, should be connected in a series circuit and needs a low internal resistance. |
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EMF |
the total work per moving charge available to an electric current. Batteries are not pure emf sources because they have internal resistance. |
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Frequency of a Wave/Wave in general |
A wave energy only transforms energy not matter and the frequency is the number of oscillations per time. The speed of a wave is determined by the medium it moves through. |
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Alpha radioactive decay |
A parent nucleus decays into a daughter nucleus and a helium nucleus (alpha particle). Can penetrate no more than a piece of paper. |
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Beta negative radioactive decay |
A nucleus changes a neutron into a proton and an electron into an anti-neutron. Can penetrate several cm of aluminum. |
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Gamma radioactive decay |
A nucleus with extra energy reduces its energy by emitting gamma rays. Can penetrate several cm of lead. |
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Strong vs. Weak Nuclear Force |
Strong holds the nucleus together, but is very short ranged, while weak is responsible for the decay of a neutron into a proton. |
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Mass Defect |
The difference between the mass of an isotope and it's mass number. The mass in the nucleus that is less than the mass of the individual neutrons and protons. |
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Binding Energy |
The mass defect has been converted into the energy needed to keep the nucleus together and becomes this. |
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Fission |
The splitting of a large nucleus into two smaller daughter nuclei, and neutrons. It is the basis for nuclear power plants. |
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Fusion |
The combining of 2 small nuclei to form a larger nucleus. It is the basis for the sun and stars energy output. |
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1st Law of Thermodynamics |
Change in Q= change in U and change in W, and heat always flows from hot to cold. |
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2nd Law of Thermodynamics |
Entropy is the energy that is lost to the surroundings. The entropy of the universe can never decrease and the net entropy of a system is always positive. |
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Simple Harmonic Motion |
An object is undergoing this motion if the acceleration of the object is directly proportional to its displacement and the acceleration is always directed towards the equilibrium position. |
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Sinusodial |
Describes a smooth repetitive oscillation. It is named after the function sine of the graph. |
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Transfer Waves |
Transfer energy in a direction perpendicular to the direction of the disturbance in the medium. A vibrating string is an example. |
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Work |
Force acting over some amount of displacement to cause a change in energy (Joules or N/m)
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Angular Frequency (W) |
The rate at which an object in SHM undergoes its phase change, measured in radians per second. |
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Damping |
Occurs when a force is applied that opposes the restoring force and decreases the Simple harmonic oscillator amplitude over time. 3 levels: lightly, critical, and over. |
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Resonance |
Occurs when an obstacle force is applied at a frequency that matches the natural frequency of the oscillator. Makes the amplitude bigger. |
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Longitudinal Wave |
A wave in which the energy flows in a direction parallel to the direction of particle oscillation. A sound wave. |
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Redshift |
The change in the wavelength of the light divided by the wavelength that the light would have if the source was not moving. |
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Blueshift |
Direct result of the Doppler Effect. The photon peaks appears to be closer together than they actually are, making the wavelength of light shorter as determined by the observer. |