Physical Quantities and SI units

Photon Energy

Plank's constant times frequency of the light E = hf, scalar, SI unit Joule (J)

Force

any influence that can change the speed or direction of an object, F = ma, vector, SI unit Newton (N) other units: pound Centripetal Force Fcp = mv^2/R Weight W = mg

Wavelength

distance between adjacent crests or troughs, scalar, SI unit meter (m)

Kinetic Energy

energy of motion, KE = 1/2 (mv^2), scalar, SI unit Joule (J)

Potential Energy

energy of position, Potential gravitational Energy PE = mgh, scalar, SI unit Joule (J)

Electric Current

flow of charge, I = Q/t, scalar, SI unit Ampere (A) Ohm Law I = V/R voltage divided by resistance

Pressure

force per surface area, p = F/A, scalar, SI unit Pascal (Pa) other units: N/m^2, lb/in^2

Displacement

length and direction of the shortest distance between the initial position and the final position, vector, SI unit meter (m)

Length

longest dimension of one object, scalar, SI unit meter (m) other units: inch, foot, yard, mile, etc.

Density

mass per unit volume, d = m/V, scalar, SI unit kilogram per cubic meter (kg/m^3)

Volume

measure of a three-dimensional space, scalar, SI unit cubic meter (m^3) other units: cubic inch, liter, etc.

Area

measure of a two-dimensional surface, scalar, SI unit square meter (m^2) other units: square inch, acres, etc.

Time

measure of duration, scalar, SI unit second (s) other units: minute, hour, etc.

Mass

measure of inertia, scalar, SI unit kilogram (kg) other units: gram, tonne, etc.

Linear Momentum

measure of the tendency of a moving object to continue moving in the same straight line at the same speed, p = mv, vector, SI unit kilogram times meter per second (kg*m/s) other units: Ns

Frequency

number of wave crests that pass a particular point per second, scalar, SI unit Hertz (Hz)

Electric Charge

physical property of matter related to the elementary particles, can be positive or negative, scalar, SI unit Coulomb (C) charges of the same sign repel, charges of opposite sign attract Coulomb Force F = KQ1Q2/r^2

Work

produced when a force acting on an object produces a displacement in the direction of the force, W = Fd, scalar, SI unit Joule (J)

Temperature

property of matter that is a measure of hot and cold, scalar, SI unit degree Kelvin (K) other units: degree Fahrenheit, degree Celsius TF = (9/5)TC + 32 TC =(5/9)TF - 32 TK = TC + 273

Speed

rate at which an object covers distance, s = d/t, scalar, SI unit meter per second (m/s) other units: miles/hour, km/h

Acceleration

rate at which one object changes velocity, a = (vf - vi)/t, vector, SI unit meter per second square (m/s^2)

Velocity

rate of change of position including direction, v = d/t, vector, SI unit meter per second (m/s) other units: miles/hour, km/h

Power

rate of producing work, P = W/t, scalar, SI unit Watt (W) other units: horsepower

Electric Power

rate to do electric work, P = IV current times voltage, scalar, SI unit Watt (W)

Energy

that property that enables work, scalar, SI unit Joule (J)

Weight

the force on an object due to gravity,W = mg, vector, SI unit Newton (N) other units: pound

Specific Heat

the heat needed to change the temperature of 1 kg of substance by 1 degree Celsius, c = Q/m(Tf - Ti), scalar, SI unit joule per kilogram Celsius (J/kgC)

Period

time for a complete wave to pass a given point, scalar, SI unit second (s)

Half-life

time needed for half of the original number of nuclides to decay, scalar, SI units seconds (s)

Heat

transfer of energy from a hotter body to a colder one, scalar, SI unit Joule (J)

Voltage

work of 1 Joule used to take a charge of 1 Coulomb form one point to another, scalar, SI Unit Volt (V) Ohm Law I = V/R voltage divided by resistance