Physics + Math Flashcards
Acceleration
A vector quantity describing a change in velocity over the elapsed time during which that change occurs, expressed as a = dv/dt. The SI unit of acceleration is m/s^2.
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.
α 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: Fbuoy = ρfluidVsubmergedg
Bernoulli’s Equiation
Equation describing the conversation of energy in fluid flow. According to the Venturi effect, for a given depth, linear flow speed and pressure are inversely related.
β 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 2 plates: C=Q/V. The SI unit for capacitance is the farad (F).
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 of 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 divided by the radius of the circle traversed: ac = v^2/r
Cohesion
A type of attractive force felt by liquid molecules (molecules of the same substance) toward each other. Cohesion is responsible for surface tension.
Conduction
Form of heat transfer where energy is transferred by molecular collisions or direct contact between two 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 and described by the equation: ΔE = ΔU + ΔK = 0
Conservative Forces
A force that does not cause dissipation of mechanical energy from a system. As such, the work performed is independent of the path taken.
ex. gravity, electrostatic forces
note: elastic forces are nearly conservative
Continuity Equation
States that the mass flow rate of fluid must remain constant from one cross-section of a tube to another, given by: A1v1 = A2v2
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. Given by the equation F = kq1q2/(r^2)
Current
A flow of charge per time. The flow of charge is motivated by a potential difference (voltage). Current is denoted I and can be calculated as Δq/Δt; Current is conventionally considered the theoretical movement of positive charge. The SI unit of current is the ampere (A).
Density
A scalar quantity defined as mass per unit volume, often denoted by ρ. Density of an object may be compared to water as a unitless quantity known as specific gravity.
Dielectric
An insulating material placed between the 2 plates of a capacitor; used to increase capacitance. The strength of a dielectric is measured by the dielectric constant.
- If the circuit is plugged into a current source, more charge will be stored
- If the circuit is NOT plugged in, the voltage of the capacitor will decrease, indirectly increase its 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: A/B = constant.
Displacement
A vector quantity describing the straight line distance between an initial and a final position of some particle or object.
Dispersion
The phenomenon observed when white light is incident on the face of a prism and emerges on the opposite sidewith all its wavelengths split apart, forming the visible spectrum. This occurs because λ is related to the index of refraction by the expression n = c/f* λ
