|  | average (indicated by a bar over a symbol—e.g.,  is average velocity) | 
          
            |  | Celsius degree | 
          
            |  | Fahrenheit degree | 
          
            |  | parallel | 
          
            |  | perpendicular | 
          
            |  | proportional to | 
          
            |  | plus or minus | 
          
            |  | zero as a subscript denotes an initial value | 
          
            |  | alpha rays | 
          
            |  | angular acceleration | 
          
            |  | temperature coefficient(s) of resistivity | 
          
            |  | beta rays | 
          
            |  | sound level | 
          
            |  | volume coefficient of expansion | 
          
            |  | electron emitted in nuclear beta decay | 
          
            |  | positron decay | 
          
            |  | gamma rays | 
          
            |  | surface tension | 
          
            |  | a constant used in relativity | 
          
            |  | change in whatever quantity follows | 
          
            |  | uncertainty in whatever quantity follows | 
          
            |  | change in energy between the initial and final orbits of an electron in an atom | 
          
            |  | uncertainty in energy | 
          
            |  | difference in mass between initial and final products | 
          
            |  | number of decays that occur | 
          
            |  | change in momentum | 
          
            |  | uncertainty in momentum | 
          
            |  | change in gravitational potential energy | 
          
            |  | rotation angle | 
          
            |  | distance traveled along a circular path | 
          
            |  | uncertainty in time | 
          
            |  | proper time as measured by an observer at rest relative to the process | 
          
            |  | potential difference | 
          
            |  | uncertainty in position | 
          
            |  | permittivity of free space | 
          
            |  | viscosity | 
          
            |  | angle between the force vector and the displacement vector | 
          
            |  | angle between two lines | 
          
            |  | contact angle | 
          
            |  | direction of the resultant | 
          
            |  | Brewster's angle | 
          
            |  | critical angle | 
          
            |  | dielectric constant | 
          
            |  | decay constant of a nuclide | 
          
            |  | wavelength | 
          
            |  | wavelength in a medium | 
          
            |  | permeability of free space | 
          
            |  | coefficient of kinetic friction | 
          
            |  | coefficient of static friction | 
          
            |  | electron neutrino | 
          
            |  | positive pion | 
          
            |  | negative pion | 
          
            |  | neutral pion | 
          
            |  | density | 
          
            |  | critical density, the density needed to just halt universal expansion | 
          
            |  | fluid density | 
          
            |  | average density of an object | 
          
            |  | specific gravity | 
          
            |  | characteristic time constant for a resistance and inductance  or resistance and capacitance  circuit | 
          
            |  | characteristic time for a resistor and capacitor  circuit | 
          
            |  | torque | 
          
            |  | upsilon meson | 
          
            |  | magnetic flux | 
          
            |  | phase angle | 
          
            |  | ohm (unit) | 
          
            |  | angular velocity | 
          
            |  | ampere (current unit) | 
          
            |  | area | 
          
            |  | cross-sectional area | 
          
            |  | total number of nucleons | 
          
            |  | acceleration | 
          
            |  | Bohr radius | 
          
            |  | centripetal acceleration | 
          
            |  | tangential acceleration | 
          
            |  | alternating current | 
          
            |  | amplitude modulation | 
          
            |  | atmosphere | 
          
            |  | baryon number | 
          
            |  | blue quark color | 
          
            |  | antiblue (yellow) antiquark color | 
          
            |  | quark flavor bottom or beauty | 
          
            |  | bulk modulus | 
          
            |  | magnetic field strength | 
          
            |  | electron’s intrinsic magnetic field | 
          
            |  | orbital magnetic field | 
          
            |  | binding energy of a nucleus—it is the energy required to completely disassemble it into separate protons and neutrons | 
          
            |  | binding energy per nucleon | 
          
            |  | becquerel—one decay per second | 
          
            |  | capacitance (amount of charge stored per volt) | 
          
            |  | coulomb (a fundamental SI unit of charge) | 
          
            |  | total capacitance in parallel | 
          
            |  | total capacitance in series | 
          
            |  | center of gravity | 
          
            |  | center of mass | 
          
            |  | quark flavor charm | 
          
            |  | specific heat | 
          
            |  | speed of light | 
          
            |  | kilocalorie | 
          
            |  | calorie | 
          
            |  | heat pump’s coefficient of performance | 
          
            |  | coefficient of performance for refrigerators and air conditioners | 
          
            |  | cosine | 
          
            |  | cotangent | 
          
            |  | cosecant | 
          
            |  | diffusion constant | 
          
            |  | displacement | 
          
            |  | quark flavor down | 
          
            |  | decibel | 
          
            |  | distance of an image from the center of a lens | 
          
            |  | distance of an object from the center of a lens | 
          
            |  | direct current | 
          
            |  | electric field strength | 
          
            |  | emf (voltage) or Hall electromotive force | 
          
            |  | electromotive force | 
          
            |  | energy of a single photon | 
          
            |  | nuclear reaction energy | 
          
            |  | relativistic total energy | 
          
            |  | total energy | 
          
            |  | ground state energy for hydrogen | 
          
            |  | rest energy | 
          
            |  | electron capture | 
          
            |  | energy stored in a capacitor | 
          
            |  | efficiency—the useful work output divided by the energy input | 
          
            |  | Carnot efficiency | 
          
            |  | energy consumed (food digested in humans) | 
          
            |  | energy stored in an inductor | 
          
            |  | energy output | 
          
            |  | emissivity of an object | 
          
            |  | antielectron or positron | 
          
            |  | electron volt | 
          
            |  | farad (unit of capacitance, a coulomb per volt) | 
          
            |  | focal point of a lens | 
          
            |  | force | 
          
            |  | magnitude of a force | 
          
            |  | restoring force | 
          
            |  | buoyant force | 
          
            |  | centripetal force | 
          
            |  | force input | 
          
            |  | net force | 
          
            |  | force output | 
          
            |  | frequency modulation | 
          
            |  | focal length | 
          
            |  | frequency | 
          
            |  | resonant frequency of a resistance, inductance, and capacitance  series circuit | 
          
            |  | threshold frequency for a particular material (photoelectric effect) | 
          
            |  | fundamental | 
          
            |  | first overtone | 
          
            |  | second overtone | 
          
            |  | beat frequency | 
          
            |  | magnitude of kinetic friction | 
          
            |  | magnitude of static friction | 
          
            |  | gravitational constant | 
          
            |  | green quark color | 
          
            |  | antigreen (magenta) antiquark color | 
          
            |  | acceleration due to gravity | 
          
            |  | gluons (carrier particles for strong nuclear force) | 
          
            |  | change in vertical position | 
          
            |  | height above some reference point | 
          
            |  | maximum height of a projectile | 
          
            |  | Planck's constant | 
          
            |  | photon energy | 
          
            |  | height of the image | 
          
            |  | height of the object | 
          
            |  | electric current | 
          
            |  | intensity | 
          
            |  | intensity of a transmitted wave | 
          
            |  | moment of inertia (also called rotational inertia) | 
          
            |  | intensity of a polarized wave before passing through a filter | 
          
            |  | average intensity for a continuous sinusoidal electromagnetic wave | 
          
            |  | average current | 
          
            |  | joule | 
          
            |  | Joules/psi meson | 
          
            |  | kelvin | 
          
            |  | Boltzmann constant | 
          
            |  | force constant of a spring | 
          
            |  | x rays created when an electron falls into an  shell vacancy from the  shell | 
          
            |  | x rays created when an electron falls into an  shell vacancy from the  shell | 
          
            |  | kilocalorie | 
          
            |  | translational kinetic energy | 
          
            |  | mechanical energy | 
            |  | kinetic energy of an ejected electron | 
      
          
            |  | relativistic kinetic energy | 
          
            |  | rotational kinetic energy | 
          
            |  | thermal energy | 
          
            |  | kilogram (a fundamental SI unit of mass) | 
          
            |  | angular momentum | 
          
            |  | liter | 
          
            |  | magnitude of angular momentum | 
          
            |  | self-inductance | 
          
            |  | angular momentum quantum number | 
          
            |  | x rays created when an electron falls into an  shell from the  shell | 
          
            |  | electron total family number | 
          
            |  | muon family total number | 
          
            |  | tau family total number | 
          
            |  | heat of fusion | 
          
            |  | latent heat coefficients | 
          
            |  | orbital angular momentum | 
          
            |  | heat of sublimation | 
          
            |  | heat of vaporization | 
          
            |  | z - component of the angular momentum | 
          
            |  | angular magnification | 
          
            |  | mutual inductance | 
          
            |  | indicates metastable state | 
          
            |  | magnification | 
          
            |  | mass | 
          
            |  | mass of an object as measured by a person at rest relative to the object | 
          
            |  | meter (a fundamental SI unit of length) | 
          
            |  | order of interference | 
          
            |  | overall magnification (product of the individual magnifications) | 
          
            |  | atomic mass of a nuclide | 
          
            |  | mechanical advantage | 
          
            |  | magnification of the eyepiece | 
          
            |  | mass of the electron | 
          
            |  | angular momentum projection quantum number | 
          
            |  | mass of a neutron | 
          
            |  | magnification of the objective lens | 
          
            |  | mole | 
          
            |  | mass of a proton | 
          
            |  | spin projection quantum number | 
          
            |  | magnitude of the normal force | 
          
            |  | newton | 
          
            |  | normal force | 
          
            |  | number of neutrons | 
          
            |  | index of refraction | 
          
            |  | number of free charges per unit volume | 
          
            |  | Avogadro's number | 
          
            |  | Reynolds number | 
          
            |  | newton-meter (work-energy unit) | 
          
            |  | newtons times meters (SI unit of torque) | 
          
            |  | other energy | 
          
            |  | power | 
          
            |  | power of a lens | 
          
            |  | pressure | 
          
            |  | momentum | 
          
            |  | momentum magnitude | 
          
            |  | relativistic momentum | 
          
            |  | total momentum | 
          
            |  | total momentum some time later | 
          
            |  | absolute pressure | 
          
            |  | atmospheric pressure | 
          
            |  | standard atmospheric pressure | 
          
            |  | potential energy | 
          
            |  | elastic potential energy | 
          
            |  | electric potential energy | 
          
            |  | potential energy of a spring | 
          
            |  | gauge pressure | 
          
            |  | power consumption or input | 
          
            |  | useful power output going into useful work or a desired, form of energy | 
          
            |  | latent heat | 
          
            |  | net heat transferred into a system | 
          
            |  | flow rate—volume per unit time flowing past a point | 
          
            |  | positive charge | 
          
            |  | negative charge | 
          
            |  | electron charge | 
          
            |  | charge of a proton | 
          
            |  | test charge | 
          
            |  | quality factor | 
          
            |  | activity, the rate of decay | 
          
            |  | radius of curvature of a spherical mirror | 
          
            |  | red quark color | 
          
            |  | antired (cyan) quark color | 
          
            |  | resistance | 
          
            |  | resultant or total displacement | 
          
            |  | Rydberg constant | 
          
            |  | universal gas constant | 
          
            |  | distance from pivot point to the point where a force is applied | 
          
            |  | internal resistance | 
          
            |  | perpendicular lever arm | 
          
            |  | radius of a nucleus | 
          
            |  | radius of curvature | 
          
            |  | resistivity | 
          
            |  | radiation dose unit | 
          
            |  | roentgen equivalent man | 
          
            |  | radian | 
          
            |  | relative biological effectiveness | 
          
            |  | resistor and capacitor circuit | 
          
            |  | root mean square | 
          
            |  | radius of the nth H-atom orbit | 
          
            |  | total resistance of a parallel connection | 
          
            |  | total resistance of a series connection | 
          
            |  | Schwarzschild radius | 
          
            |  | entropy | 
          
            |  | intrinsic spin (intrinsic angular momentum) | 
          
            |  | magnitude of the intrinsic (internal) spin angular momentum | 
          
            |  | shear modulus | 
          
            |  | strangeness quantum number | 
          
            |  | quark flavor strange | 
          
            |  | second (fundamental SI unit of time) | 
          
            |  | spin quantum number | 
          
            |  | total displacement | 
          
            |  | secant | 
          
            |  | sine | 
          
            |  | z-component of spin angular momentum | 
          
            |  | period—time to complete one oscillation | 
          
            |  | temperature | 
          
            |  | critical temperature—temperature below which a material becomes a superconductor | 
          
            |  | tension | 
          
            |  | tesla (magnetic field strength B) | 
          
            |  | quark flavor top or truth | 
          
            |  | time | 
          
            |  | half-life—the time in which half of the original nuclei decay | 
          
            |  | tangent | 
          
            |  | internal energy | 
          
            |  | quark flavor up | 
          
            |  | unified atomic mass unit | 
          
            |  | velocity of an object relative to an observer | 
          
            |  | velocity relative to another observer | 
          
            |  | electric potential | 
          
            |  | terminal voltage | 
          
            |  | volt (unit) | 
          
            |  | volume | 
          
            |  | relative velocity between two observers | 
          
            |  | speed of light in a material | 
          
            |  | velocity | 
          
            |  | average fluid velocity | 
          
            |  | change in potential | 
          
            |  | drift velocity | 
          
            |  | transformer input voltage | 
          
            |  | rms voltage | 
          
            |  | transformer output voltage | 
          
            |  | total velocity | 
          
            |  | propagation speed of sound or other wave | 
          
            |  | wave velocity | 
          
            |  | work | 
          
            |  | net work done by a system | 
          
            |  | watt | 
          
            |  | weight | 
          
            |  | weight of the fluid displaced by an object | 
          
            |  | total work done by all conservative forces | 
          
            |  | total work done by all nonconservative forces | 
          
            |  | useful work output | 
          
            |  | amplitude | 
          
            |  | symbol for an element | 
          
            |  | notation for a particular nuclide | 
          
            |  | deformation or displacement from equilibrium | 
          
            |  | displacement of a spring from its undeformed position | 
          
            |  | horizontal axis | 
          
            |  | capacitive reactance | 
          
            |  | inductive reactance | 
          
            |  | root mean square diffusion distance | 
          
            |  | vertical axis | 
          
            |  | elastic modulus or Young's modulus | 
          
            |  | atomic number (number of protons in a nucleus) | 
          
            |  | impedance |