Physical Quantities

Physical Quantities

	Quantity	Definition	Formula	Units	Dimensions
	Length or Distance	fundamental	d	m (meter)	L (Length)
	Time	fundamental	t	s (second)	T (Time)
	Mass	fundamental	m	kg (kilogram)	M (Mass)
	Area	distance2	A = d2	m2	L2
	Volume	distance3	V = d3	m3	L3
	Density	mass / volume	d = m/V	kg/m3	M/L3
	Velocity	distance / time	v = d/t	m/s c (speed of light)	L/T
	Acceleration	velocity / time	a = v/t	m/s2	L/T2
	Momentum	mass × velocity	p = m·v	kg·m/s	ML/T
	Force   Weight	mass × acceleration mass × acceleration of gravity	F = m·a W = m·g	N (newton) = kg·m/s2	ML/T2
	Pressure or Stress	force / area	p = F/A	Pa (pascal) = N/m2 = kg/(m·s2)	M/LT2
	Energy or Work   Kinetic Energy   Potential Energy	force × distance mass × velocity2 / 2 mass × acceleration of gravity × height	E = F·d KE = m·v2/2 PE = m·g·h	J (joule) = N·m = kg·m2/s2	ML2/T2
	Power	energy / time	P = E/t	W (watt) = J/s = kg·m2/s3	ML2/T3
	Impulse	force × time	I = F·t	N·s = kg·m/s	ML/T
	Action	energy × time momentum × distance	S = E·t S = p·d	J·s = kg·m2/s h (quantum of action)	ML2/T
	Angle	fundamental	θ	° (degree), rad (radian), rev 360° = 2π rad = 1 rev	dimensionless
	Cycles	fundamental	n	cyc (cycles)	dimensionless
	Frequency	cycles / time	f = n/t	Hz (hertz) = cyc/s = 1/s	1/T
	Angular Velocity	angle / time	ω = θ/t	rad/s = 1/s	1/T
	Angular Acceleration	angular velocity / time	α = ω/t	rad/s2 = 1/s2	1/T2
	Moment of Inertia	mass × radius2	I = m·r2	kg·m2	ML2
	Angular Momentum	radius × momentum moment of inertia × angular velocity	L = r·p L = I·ω	J·s = kg·m2/s ћ (quantum of angular momentum)	ML2/T
	Torque or Moment	radius × force moment of inertia × angular acceleration	τ = r·F τ = I·α	N·m = kg·m2/s2	ML2/T2
	Temperature	fundamental	T	°C (celsius), K (kelvin)	K (Temp.)
	Heat	heat energy	Q	J (joule) = kg·m2/s2	ML2/T2
	Entropy	heat / temperature	S = Q/T	J/K	ML2/T2K
	Electric Charge +/-	fundamental	q	C (coulomb) e (elementary charge)	C (Charge)
	Current	charge / time	i = q/t	A (amp) = C/s	C/T
	Voltage or Potential	energy / charge	V = E/q	V (volt) = J/C	ML2/CT2
	Resistance	voltage / current	R = V/i	Ω (ohm) = V/A	ML2/C2T
	Capacitance	charge / voltage	C = q/V	F (farad) = C/V	C2T2/ML2
	Inductance	voltage / (current / time)	L = V/(i/t)	H (henry) = V·s/A	ML2/T2
	Electric Field	voltage / distance force / charge	E = V/d E = F/q	V/m = N/C	ML/CT2
	Electric Flux	electric field × area	ΦE = E·A	V·m = N·m2/C	ML3/CT2
	Magnetic Field	force / (charge × velocity)	B = F/q·v	T (tesla) = Wb/m2 = N·s/(C·m)	M/CT
	Magnetic Flux	magnetic field × area	ΦM = B·A	Wb (weber) = V·s = J·s/C	ML2/CT

Note: Other conventions define different quantities to be fundamental.

Mass, energy, momentum, angular momentum, and charge are conserved, which means the total amount does not change in an isolated system.

Posted in: fisika SMA, Physical Quantities