Kaplan Flashcards
Acceleration
A vector quantity describing a change in velocity over the elapsed time during which that change occurs
Adhesion
A type of attractive force that molecules of a liquid fell toward molecules of another substance, such as in the adhesion of water droplets to a glass surface
Alpha Decay
A nuclear reaction in which an α - particle is emitted
Archimedes’ Principle
States that a body that is fully or partially immersed in a liquid will be buoyed upwards by a force that is equal to the weight of the liquid displaced by the body
Bernoulli’s Equation
Equation describing the conservation of energy in fluid flow
Beta Decay
A nuclear reaction in which a β-particle (e-) is emitted
Binding Energy
The energy that holds the protons and neutrons together in the nucleus, defined by the equation e=mc^2, where m is the mass defect and c is the speed of light in a vacuum
Capacitance
A measure of a capacitor’s ability to store charge at a given voltage; calculated by the ratio of the magnitude of charge on one plate to the voltage across the two plates
- SI unit : farad (F)
Capacitor
An electric device is used in circuits that is composed of 2 conducting plates separated by a short distance; these devices store electric charge
Center of Mass
The point on some object or body where all of its mass is considered to be concentrated. In a uniform gravitational field, this is also the center of gravity
Centripetal Acceleration
The acceleration of an object traveling in a circle that points toward the center of the circle. In uniform circular motion, it is equal in magnitude to the velocity squared by the radius of the circle traversed
Cohesion
A type of attractive force felt by liquid molecules toward each other. It is responsible for surface tension
Conduction
Form of heat transfer where energy is transferred by molecular collisions or direct contact between 2 objects
Conductor
A material in which electrons can move with relative ease
Conservation of Mechanical Energy
States that when only conservative forces act on an object and work is done, energy is conserved
Conservative Force
A force that does not cause dissipation of mechanical energy from a system. As such, the work is performed independent of the path taken
- Gravity and electrostatic forces
Continuity Equation
States that the mass flow rate of fluid must remain constant from one cross-section of a tube to another
Convection
Form of heat transfer where a heated fluid transfers energy by bulk flow and physical motion over another object, or a cooled fluid absorbs energy by the same means
Coulomb’s Law
The law describing the electrostatic force that exists between 2 charges, q1 and q2, that are separated by a distance r
Current
A flow of charge per time. The flow of charge is motivated by a potential difference (voltage)
- SI unit: ampere (A)
Density
A scalar quantity defined as mass per unit volume
Dielectric
An insulating material placed between the 2 plates of a capacitor; used to increase capacitance
Diffraction
The spreading-out effect of light when it passes through a small, slit opening
Direct Relationship
A relationship between variables such that an increase in one variable is associated with an increase in the other
Dispersion
The phenomenon observed when white light is incident on the face of a prism and emerges on the opposite side with all its wavelengths split apart. forming the visible spectrum
Displacement
A vector quantity describing the straight-line distance between an initial and a final position of some particle or object
Doppler Effect
When a source emitting a sound and a detector receiving the sound move relative to each other, the perceived frequency f’ is less than or greater than the actual frequency emitted f, depending on whether the source and detector move toward or away from each other
Elastic Potential Energy
The energy associated with stretching or compressing a spring
- SI unit: joules (J)
Electric Circuit
A conducting pathway that contains one or more voltage sources that drive an electric current along that pathway and through connected passive circuit elements
Electric Field
The electrostatic force that a source charge would exert on a positive test charge q0 divided by the magnitude of that test charge. Represented by electric field lines-imaginary lines that show the direction in which a positive test charge is accelerated by the coulombic force due to the electric field of a source charge
- SI unit: N/C or V/m
Electric Potential
The amount of electric potential energy per unit charge; the work required to bring a positive test charge q0 from infinity to within an electric field of another positive source charge, Q. divided by that test charge’s magnitude
- SI unit: volt (V)
Electric Potential Energy
The amount of work required to bring a test charge q0 from infinity to a point within the electric field of some source charge, Q
- SI unit: joule (J)
Electric Power
The rate at which the energy of flowing charges through a resistor or other device is dissipated
- SI unit: watt (W)
Electromagnetic Spectrum
The full range of frequencies and wavelengths for electromagnetic waves broken down into the following regions (in descending order of wavelength): radio, infrared, visible light, ultraviolet, x-ray, and gamma ray
Electromagnetic Waves
When an electric field is changing, it causes a change in a magnetic field and vice versa, resulting in the propagation of a wave containing an electric and a magnetic field that are perpendicular to each other
Heat of Transformation
The amount of heat required to change the phase of a substance
- Solid-liquid change —> heat of fusion
- Liquid-gas change —> heat of vaporization
Heat Transfer
The movement of thermal energy toward a state of thermodynamic equilibrium
- Higher temperature to lower temperature
Image
The apparent location of an object perceived through a lens or mirror
- Real and virtual
Gravity
A ubiquitous attractive force existing between any two objects, with magnitude directly proportional to the product of the 2 masses observed and inversely proportional to the square of their distance from each other
Half-Life
The amount of time it takes for 1/2 of a radioactive sample to decay
Snell’s Law
Equation describing the angle of refraction for a light ray passing from one medium to another
Speed of Light
The speed of electromagnetic waves traveling though a vacuum
Spherical Mirror
Have the appearance of a curved surface that is either concave or convex
Sound Level
The loudness of a sound, measured in decibels (dB)
Speed
A scalar quantity describing the distance traveled divided by the time required to travel that distance
- SI unit: meters per second (m/s)
Insulator
A material in which electrons cannot move freely
Index of Refraction
Ratio of the speed of light in a vacuum to the speed of light through a medium
Interference
When superimposed waves are in phase, their amplitudes add (constructive). When superimposed light waves are out of phase, their amplitudes subtract (destructive)
Inverse Relationship
A relationship between variables such that an increase in one variable is associated with a decrease in the other
Kinetic Energy
The energy of an object in motion
- SI unit: joules (J)
Kirchhoff’s Junction Rule
States that the sum of currents directed into a node or junction point in a circuit equals the sum of the currents directed away from that point
Kirchhoff’s Loop Rule
States that the sum of the voltage sources in a circuit loop is equal to the sum of the voltage drops along that loop
Laminar Flow
The smoothest type of liquid flow through a tube wherein thin layers of liquid slide over one another
Law of Reflection
States that when light waves strike a medium, the angle of incidence Θi is equal to the angle of reflection Θr
Lens
A transparent device with a curvature that causes light to bend as it passes through
Logarithm
A mathematical function that is the inverse of the exponential function
- Common or natural
Magnification
A dimensionless value
- negative denotes inverted images
- positive denotes upright image
Mass
A scalar quantity used as a measure of an object’s inertia
- SI unit: kilogram (kg)
Mass Defect
The difference between an atom’s atomic mass and the sum of the masses of its protons and neutrons
Newton’s First Law
States that if no net force acts on an object, its velocity is constant
Gravitational Potential Energy
The energy of an object due to its height above a given datum
- SI unit: joules (J)
Normal Force
Perpendicular component of the force caused when two surfaces push against each other (N)
Nonconservative Force
A force that dissipates mechanical energy from a system
Newton’s Second Law
States that an object will accelerate in proportion to the net force acting on it
Newton’s Third Law
States that if one object exerts a force on another, the other object exerts a force on the first that is equal in magnitude but opposite in direction
Gauge Pressure
The pressure above and beyond atmospheric pressure
Frequency
Number of cycles per second measured in units of Hz
Frictional Force
An antagonistic force that points parallel and opposite in direction to the direction of movement of an object
Gamma Decay (γ)
A nuclear reaction in which high-energy photons are emitted
First Law of Thermodynamics
States that the change in internal energy of a system is equal to the heat transferred into the system minus the work done by the system
Focal Length
The distance between the focal point and the mirror or lens
Force
A vector quantity describing the push or pull on an object
- SI unit: newton (N)
Electromotive Force
The impetus for current flow created by a voltage source
- Measured in volts (V)
Equipotential Lines
Concentric circles emanating from a source charge that cross its electric field lines perpendicularly
Exponential Decay
A decrease in the amount of substance N at an exponential rate
Right-Hand Rule
A common method used to determine the direction of a vector created as the product of 2 vectors
- Thumb points in direction of 1st vector, fingers point in direction of 2nd vector, palm points in direction of resultant
Rotational Equilibrium
State where the sum of the torques acting on a body is zero, giving it no net angular acceleration
Scalar
A quantity that has magnitude but no direction
Radiation
Form of heat transfer where the energy is carried by electromagnetic waves
- Can be carried out in a vacuum
Resistance
The natural tendency of a conductor to block current flow to a certain extent resulting in loss of energy or potential
- SI unit: ohm (Ω
Resistivity
Intrinsic property of a conductor used to measure its resistance
- SI unit: ohm-meter (Ω-m)
Potential Difference
The difference in electric potential between 2 points in an electric field
- Also called voltage
Power
The rate at which work is done
- SI unit: watt (W)
Pressure
The force per unit area
- SI unit: pascal (Pa)
Plane Mirror
A mirror in which incident light rays remain parallel after reflection, always producing a virtual image that appears to be the same distance behind the mirror as the object is in front of the mirror
Plane-Polarized Light
Light that has been passed through a polarizing filter, allowing only the transmission of waves containing electric field vectors parallel to the lines of the filter
Positron Decay (β +)
A nuclear reaction in which a positron is emitted
Pascal’s Principle
States that when a pressure is applied to one point of an enclosed fluid, that pressure is transmitted in equal magnitude to all points within that fluid and to the walls of its container
Photoelectric Effect
The phenomenon observed when the light of a certain frequency causes a metal to emit electrons
Ohm’s Law
Law stating that the voltage drop across a resistor is proportional to the current flowing through it
- Measured in volts (V)
Vector
A quantity that has both magnitude and direction
Velocity
A vector quantity describing an object’s displacement over the elapsed time
- SI unit: meters per second (m/s)
Viscosity
The measure of internal friction in a fluid, often denoted by η
Total Internal Reflection
The condition in which the incident angle of light traveling from a medium with a high n to a medium with a low n is greater than the critical angle
- No light refracted
Translational Equilibrium
State where the sum of the forces acting on an object is zero, giving it no net acceleration
Turbulent Flow
Type of liquid flow that occurs when the linear flow speed in a tube exceeds the critical speed
- Vortices and high resistance
Second Law of Thermodynamics
States that for any process, the entropy of the universe either increases or remains constant
Zeroth Law of Thermodynamics
States that 2 objects that are in thermal equilibrium with a third object are also in thermal equilibrium with each other
Torque
A force creating rotation about an axis
- SI unit: newton meter (N.m)
Wave Speed
The speed of a wave
Wavelength
A quantity equal to the distance between any 2 equivalent consecutive points along a wave
- SI unit: meter (m)
Work
Energy transfer in which a force is applied to change the energy of a system
- SI unit: joule (J)
Work-Energy Theorem
States that the net work performed on an object is related to its change in energy
