Physics Flashcards
Law stating that the voltage drop across a resistor is proportional to the current flowing through it, given by the equation V = IR.
Ohm’s Law
A quantity that has magnitude but no direction.
Scalar
States that the sum of currents directed into a node or junction point in a current equals the sum of the currents directed away from that point.
Kirchhoff’s Junction Rule
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.
Convection
The impetus for current flow created by a voltage source, such as a battery or outlet.
Electromotive Force
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; the law of “action and reaction.”
Newton’s Third Law
The rate at which the energy of flowing charges through a resistor or other device is dissipated, given by the equation P = IV.
Electric Power
A quantity that has both magnitude and direction.
Vector
Spherical mirrors have the appearance of a curved surface that is either concave or convex. A converging mirror is a concave mirror with a positive focal length, while a diverging mirror is a convex mirror with a negative focal length. Diverging mirrors always produce virtual images.
Spherical Mirror
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.
Adhesion
Form of heat transfer where the energy is carried by electromagnetic waves; the only form of heat transfer that can be carried out in a vacuum.
Radiation
State where the sum of the torques acting on a body is zero, giving it no net angular acceleration. An object may be in rotational equilibrium, translational equilibrium, or both simultaneously.
Rotational Equilibrium
A vector quantity describing the push or pull on an object. The SI unit for force is the newton (N).
Force
States that if no net force acts on an object, its velocity is constant.
Newton’s First Law
A force that does not cause dissipation of mechanical energy from a system. As such, the work performed is independent of the path taken. Examples include gravity and electrostatic forces. Elastic forces are nearly conservative.
Conservative Force
A scalar quantity describing the distance traveled divided by the time required to travel that distance.
Speed
State where the sum of the forces acting on an object is zero, giving it no net acceleration. An object may be in rotational equilibrium, translational equilibrium, or both simultaneously.
Translational Equilibrium
A scalar quantity used as a measure of an object’s inertia.
Mass
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).
Electric Circuit
A transparent device with a curvature that causes light to bend (refract) as it passes through. May be converging or diverging. A lens with a thick center that converges light rays at a point where the image is formed is called a converging lens. A lens with a thin center that diverges light after refraction and always forms a virtual image is called a diverging lens.
Lens
The natural tendency of a conductor to block current flow to a certain extent resulting in loss of energy or potential. Resistance is equal to the ratio of the voltage applied to the resulting current.
Resistance
Form of heat transfer where energy is transferred by molecular collisions or direct contact between two objects.
Conduction
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.
Plane-Polarized Light
When superimposed waves are in phase, their amplitudes add (constructive interference). When superimposed light waves are out of phase, their amplitudes subtract (destructive interference).
Interference
A type of attractive force felt by liquid molecules toward each other. Cohesion is responsible for surface tension.
Cohesion
An insulating material placed between the two plates of a capacitor; used to increase capacitance. 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 increasing its capacitance. The strength of a dielectric is measured by the dielectric constant.
Dielectric
States that the sum of the voltage sources in a circuit loop is equal to the sum of voltage drops along that loop.
Kirchhoff’s Loop Rule
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.
Focal Length
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 Mirror
A force that dissipates mechanical energy from a system. As such, the energy dissipated depends on the path taken from initial to final position. Examples include friction, air resistance, and viscous drag.
Nonconservative Force
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. This principle forms the basis of the hydraulic lift.
Pascal’s Principle
The spreading-out effect of light when it passes through a small slit opening.
Diffraction
Perpendicular component of the force caused when two forces push against each other, denoted by N.
Normal Force
The movement of thermal energy towards a state of thermodynamic equilibrium. Heat spontaneously transfers energy from the object with the higher temperature to the object with the lower temperature.
Heat Transfer
A relationship between variables such that an increase in one variable is associated with a decrease in the other: AB = constant.
Inverse Relationship
States that the net work performed on an object is related to its change in energy. In most applications, the work-energy theorem is used to relate work and kinetic energy.
Work-Energy Theorem
A material in which electrons cannot move freely.
Insulator
A material in which electrons can move with relative ease.
Conductor
The energy of an object due to its height above a given datum, calculated by the equation U = mgh and given in the SI unit of joules (J).
Gravitational Potential Energy
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.
Center of Mass
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.
Equipotential Lines