Letter	Variable or constant	Unit	Equations with variable
A		amperes (current)
a	acceleration		$a=\frac{\Delta ѵ}{\Delta t}$
BMI	body mass index		$\mathrm{BMI}=\frac{m}{h\mathrm{²}}$
c	speed of light	centi- prefix: cm	E = mc²
d	distance		d = ѵt, d = 0.5at², d = 0.5gt²
Δ%	percent difference		$\Delta \%=\frac{(\text{observed}-\mathrm{predicted})}{\mathrm{predicted}}$
F	force		$F=\frac{\Delta p}{\Delta t}$, F = ma, F = −kx
f	frequency f		f = 1 ÷ τ
h	height, Planck constant
i	current, $\sqrt{-1}$
g	acceleration of gravity	grams	d = 0.5gt²
GPE	gravitational potential energy		GPE = mgh
KE	kinetic energy		KE = 0.5mѵ²
k	Hooke's constant, y-coor. quadratic vertex		F = kx, $y=-\left(\frac{k}{r^2}\right)x^2+k$
l	length	liters (liquid volume)
λ	wavelength		ѵ = λf
m	mass or slope	meters	m = ρV, $\text{slope m}=\frac{(\mathrm{y2}-\mathrm{y1})}{(\mathrm{x2}-\mathrm{x1})}$
Ω		Ohms (Resistance)	V = iR
P	Power		P = iV
p	momenturm		p = mѵ
ρ	density		m = ρV
R	Resistance		V = iR
s	arc length	seconds
T	temperature
t	time
τ	period		τ = 1 ÷ f
V	volume, voltage	Volts	V = lwh, V = iR
ѵ	velocity		$v=\frac{\Delta d}{\Delta t}$, ѵ = at
W	work (energy)	Watts (power)
w	width		V = lwh