Physics and Math Flashcards
Half-Life
The amount of time it takes for one-half of a radioactive sample to decay, given by the equation: T1/2= ln2/lambda.
Adhesion
A type of attractive force that molecules of a liquid feel 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 alpha particle is emitted.
A A-4 4
X => Y + He
Z Z-2 2
Beta Decay
A nuclear reaction in which a B-particle is emitted:
A A
X => Y + B-
Z Z+1
Capacitor
An electric device used in circuits that is composed of two 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.
Cohesion
A type of attractive force felt by liquid molecules toward each other. Cohesion is responsible for surface tension.
Conductor
A material in which electrons can move with relative ease.
Conservative Force
A force that does not cause dissipation of mechanical energy from a system. As such, the work perfromed is independent of the path taken. Examples include gravity and electrostatic forces. Elastic forces are nearly conservative.
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.
Density
A scalar quantity defined as mass per unit volume, often denoted by p. Density of an object may be compared to water as a unitless quantity known as specific gravity.
Direct Relationship
A relationship between variables such that an increase in one variable is associated with an increase in the other:
A/B = constant.
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. This occurs because wavelength (l) is related wo the index of refraction by the expression n=c/fl
Displacement
A vector quantity describing the straight-line distance between an initial and a final position of some particle or object.
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 (such as resistors).
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, resultingin the propagation of a wave containing an electric and a magnetic field that are perpendicular to each other.
Electromotive Force
The impetus for current flow created by a voltage source, such as a battery or outlet. Electromotive force is measured in volts (V).
Equipotential Lines
Concentric circles emanating from a source charge that cross its electric field lines perpendicularly. No work is required for a test charge to travel along the circumference of an equipotential line, because the potential at every point along that line is the same.
Focal Length
The distance between the focal point and the mirror or lens. For spherical mirrors, the focal length is equal to one-half the radius of curvature.
Force
A vector quantity describing the push or pull on an object. The SI unit for force is the newton (N).
Frequency
Number of cycles per second measured in units of Hz, where 1 Hz = 1 cycle per second.
Gamma Decay
A nuclear reaction in which high-energy photons, also known as gamma particles, are emitted:
A A
X* => X + gamma
Z Z
Heat Transfer
The movement of thermal energy toward a state of thermodynamic equilibrium. Heat spontaneously transfers energy from the object with the higher temperature to the object with the lower temperature.