EXAMBUSTERS GENERAL PHYSICS MCAT
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- Vector Quantity
- Has magnitude and direction; and usually a unit of measure (The symbol is →) A vector can represent displacement, velocity, acceleration
- Scalar Quantity
- A quantity that is fully specified by giving its magnitude (mass or speed)
- Are the following scalar or vector: 1) speed; 2) weight; 3) mass; 4) velocity
- 1) scalar; 2) vector; 3) scalar; 4) vector
- Newton's First Law
- A body at rest stays at rest and a body in motion stays in motion at constant velocity if no net force acts on it
- Contrast Speed vs. Velocity
- Speed has only magnitude. Velocity is a vector having magnitude and direction.
- Equation for distance at constant velocity
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see equation - Force
- A vector quantity which is a push or pull exerted on a body.
- Newton's Second Law
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Newton's Second Law - Uniformly Accelerated Motion
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Uniformly Accelerated Motion - Velocity Equation for Uniform Acceleration
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Velocity Equation for Uniform Acceleration - Acceleration Equation
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Acceleration Equation - Equation for final velocity with uniform acceleration
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Equation for final velocity with uniform acceleration - Equation for average speed with constant acceleration (not starting from rest)
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Equation for average speed with constant acceleration (not starting from rest) - Describe a force in terms of its components
- A single force may be replaced by two or more forces (its component forces). These are vectors which, by using vector addition, add up to the original force.
- Torque
- The effectiveness of a force in producing rotation. Also called moment of force.
- Newton's Law of Universal Gravitation
- Two objects attract each other each other with a force that is proportionate to the product of their masses and inversely proportionate to the square of distance between them.
- Center of Gravity
- A point in or on the object where all the weight is concentrated. If supported only at this point the object will be in balance.
- Equation for average speed with constant acceleration (starting from rest
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Equation for average speed with constant acceleration (starting from rest - Inertia
- The property by which an object resists being accelerated.
- After 6 seconds, how far will a body fall in a vacuum (g=32)
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After 6 seconds, how far will a body fall in a vacuum (g=32) - With acceleration constant at 10 m/s2 and an initial velocity of 3 m/s, how far will a body move in 7 s?
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With acceleration constant at 10 m/s2 and an initial velocity of 3 m/s, how far will a body move in 7 s? - With an initial velocity of 4 ft/s and a constant aceleration of 7 ft/sec2, what is the velocity after 12 s?
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With an initial velocity of 4 ft/s and a constant aceleration of 7 ft/sec2, what is the velocity after 12 s? - Formula for final velocity given the distance s, the acceleration a, and the initial velocity Vi.
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Formula for final velocity given the distance s, the acceleration a, and the initial velocity Vi. - Which force is referred to in Newton's second law when there is more than one force on a body
- The vector sum of all forces.
- Newton's Third Law
- When one object exerts a force on a second object, the second object exerts an equal and opposite force on the first (action equals reaction.)
- Centripetal Force
- The inward force that must be applied to keep a body moving in a circle
- Equation for Centripetal Acceleration
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Equation for Centripetal Acceleration - For liner motion with constant acceleration, what are the formulas for 1) distance, 2) velocity, 3) average velocity, 4) final velocity independent of time
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For liner motion with constant acceleration, what are the formulas for 1) distance, 2) velocity, 3) average velocity, 4) final velocity independent of time - Frame of Reference
- any system for specifying the precise location of objects in space. Your frame of reference is where you view the scene from. Ex. From a moving airplane or standing in your living room
- Conservation of Momentum
- In a closed system where no external forces act, the total momentum of the system is conserved.
- Equation for Newton's Law of Gravitation
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Equation for Newton's Law of Gravitation - Work; Equation for Work
- The product of the force on an object and the distance the object moves in the direction of the force. W = Fd; W=work in joules; F=force in Newtons; d=distance in meters
- Potential Energy; Equation for Potential Energy
- The energy stored by an object because of its position or its condition. Ex. A skier on top of a mountain has potential energy. PE = wh = mgh; w=weight; h=object height; m=mass; g=constant gravitation; PE=potential energy
- Kinetic Energy; Equation for Kinetic Energy
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Kinetic Energy; Equation for Kinetic Energy - Equation for coefficient of sliding friction
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Equation for coefficient of sliding friction - Equation for work against friction
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Equation for work against friction - Power; Equation for Power
- The measure of how much work gets done per unit time; measured in watts. 1 watt = 1 joule/sec; P=W/t = Fd/t; P=power (watts); W=work (joules); t=time in seconds; F=force in newtons; d=distance in meters.
- Equation for Momentum
- P = mv; m=mass; v=velocity; P=momentum
- Line of Force
- A line drawn so that a tangent to it at any point indicates the direction of an electric or magnetic field.
- Normal Force
- A force perpendicular to the surface of an object. When you press down on the object, the normal force presses up.
- Hooke's Law
- F = -(k)x; k=spring constant; x=distortion distance; F=distortion force
- Equation for work done in stretching a spring
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Equation for work done in stretching a spring - Equation for Change in Length when a solid expands or contracts
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Equation for Change in Length when a solid expands or contracts - Archimedes Principle
- The apparent loss in weight of an object immersed in a fluid equals the weight of the displaced fluid.
- Bernoulli's Principle
- The greater the velocity of a fluid, the smaller its pressure.
- Equation for liquid pressure in a beaker
- P=hdg; h=height of the liquid level; d=liquid density; g=gravitational constant; P=pressure
- Two insoluble objects lose the same weight in a fluid, the objects must have the same⬦
- Volume. Using Archimedes Principle: the apparent loss in weight is equal to weight of the displaced fluid. They displace the same volume.
- Crest
- A region of upward displacement in a transverse wave.
- Trough
- A region of downward displacement in a transverse wave.
- Amplitude
- The maximum displacement of a vibrating particle from its equilibrium position. The height of the wave.
- Wavelength
- In a periodic wave, the distance between two adjacent troughs or two crests (λ)
- Transverse Wave
- A wave in which the vibration are at right angles to the direction of propagation of the wave. Ex, electromagnetic waves.
- Periodic Wave
- A wave repeated in each of a succession of equal time intervals.
- Longitudinal Wave
- A wave in which the vibrations are parallel to the direction of propagation of the wave. Ex. Sound waves.
- Hertz
- The frequency of sound waves. 1 hz = 1 cycle per second.
- Decibel
- A unit of sound intensity level
- Compression
- The region of a longitudinal wave in which the vibrating particles are closer than their equilibrium distance.
- Rarefaction
- The region in a longitudinal wave where vibrating particles are farther apart than the equilibrium distance.
- Beats
- When two notes of slightly different frequencies reach the ear at the same time. A burst of sound followed by silence
- Constructive Interference
- When two waves make the medium vibrate in the same direction they reinforce and make a bigger disturbance
- Destructive Interference
- When two waves make a medium vibrate in opposite directions, they tend to cancel each other. This will result in a smaller wave or one that disappears completely.
- Doppler Effect
- When there is relative motion between a source of a wave and an observer, the frequency of vibrations received by the observer increases if the source and observer approach each other and decreases when the source and observer distance is increasing. Ex, the pitch of a siren changes as it approaches and passes you.
- Law of Reflection
- When a wave is reflected, the angle of incidence equals the angle of reflection.
- Regular Reflection
- from smooth flat surfaces, incident waves in the same plane are reflected in the same plane. Ex. A plane mirror
- Diffuse Reflection
- from rough and irregular surfaces, reflected light waves go in many directions. Ex. A piece of paper.
- Concave Mirror
- Reflecting surface is the inside of a spherical shell
- Convex Mirror
- Reflecting surface is the outside of a spherical shell
- Equation for focal length of a spherical mirror
- f=R/2; R=radius of the spherical shell; f=focal length
- Angle of Incidence
- Angle between the incident light and the normal to the reflecting surface
- Angle of Reflection
- Angle between the reflected light ray and the normal to the reflecting surface
- Refraction
- The bending of a wave on going into a second medium; eg, a light wave bends when going from air to water
- Critical Angle
- The limiting angle of incidence in the optically denser medium that results in an angle of refraction of 90 degrees
- Snell's Law
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Snell's Law - Convex Lens
- A convex lens is thicker in the middle than at the edges; it is also called a converging lens
- Concave Lens
- A concave lens is thinner in the middle than at the edges; it is also called a diverging lens.
- Focal Length
- The distance from the principal focus to the lens or mirror
- Index of Refraction
- A measure of the angle or degree an electromagnetic wave bends when travelling from one substance to another. Ex. Put a pencil in a bowl of water, the pencil will appear bent because the light waves bend when going from water to air.
- Lens Equation
- 1/p + 1/q = 1/r; p=object distance; f=focal length; q=image distance
- Equation relating object and image sizes for lens.
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Equation relating object and image sizes for lens. - Equation for telescopic magnification
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Equation for telescopic magnification - Huygen's Principle
- Each point on a wave front may be regarded as a new source of disturbance
- Diffraction
- the bending of a wave around obstacles
- Polarized Light
- Light whose direction of vibration has been restricted into one plane of vibration
- Virtual Image
- A mirror or lens image formed by the eye and brain which can not be projected on a screen. Ex, the image you see of yourself in the mirror
- Equation for the Focal Length of a spherical mirror of radius R
- F=R/2; F=focal length; R=radius
- Formula for the Index of Refraction
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Formula for the Index of Refraction - Formula for Coulomb's Law
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Formula for Coulomb's Law - Equation for Electric Field Intensity
- E = F/Q; E=electric field intensity; F= force exerted; Q=charge
- Equation for Potential Difference between two points
- V=W/Q; V=voltage (volts); Q=charge (coulombs); W=work (joules)
- Parallel Circuit
- Where resistors in a circuit are connected independent of each other. Circuit is in the form of several loops.
- Series Circuit
- Where resistors are connected so that the current flows from the tip of one to the tail of another
- Formula for Current in a series circuit (Ohm's Law applied)
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Formula for Current in a series circuit (Ohm's Law applied) - Formula for current in a parallel circuit (Ohm's Law applied)
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Formula for current in a parallel circuit (Ohm's Law applied) - Formula for Resistance in a series circuit (Ohm's Law applied)
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Formula for Resistance in a series circuit (Ohm's Law applied) - Formula for Resistance in a parallel circuit (Ohm's Law applied)
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Formula for Resistance in a parallel circuit (Ohm's Law applied) - Formula for voltage in a series circuit (Ohm's Law applied)
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Formula for voltage in a series circuit (Ohm's Law applied) - Formula for voltage in a parallel circuit (Ohm's Law applied)
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Formula for voltage in a parallel circuit (Ohm's Law applied) - Formula for Ohm's Law
- V = IR; V=voltage in volts; I = current in amperes; R=resistance in ohms
- Law of Magnets
- Like poles repel, unlike poles attract. North repels north; south repels south; north attracts south
- Magnetic Field
- The region where a magentic influence can be detected as a force on a magnet
- Left-Hand Rule
- Grasp the wire with the left hand so that the thumb will point in the direction of the electron flow; fingers will then direct towards flux lines.
- Electromagnet strength depends upon which three things
- 1) The number of turns in the coil of the solenoid; 2) the nature of the core; 3) The current through the core.
- Galvenometer
- Instrument which measures low values of current.
- Voltmeter
- an instrument calibrated to measure the potential difference connected to its terminals.
- Alternating Current (AC)
- Current whose direction is constantly reversing. This is the type of current you get from the wall outlet.
- Direct Current (DC)
- Current whose direction is one path, never reversing. This is the type of current you get from a battery.