D	Diffusion coefficient
E	Energy absorbed
E′	Storage modulus
E″	Loss modulus
Ea	Absorbed energy
Ei	Incident wave energy
g	Acceleration due to gravity
H	height of impact
Hz	Frequency
h	Sample thickness
k	$\mathrm{Slope} \mathrm{of} \mathrm{the} \mathrm{plot} \mathrm{between} W_t$ $\mathrm{and} \sqrt{t}$
m	mass of projectile
n	Constant
$S_C$	Sorption coefficient
t	Time taken to absorb in seconds
Tg	Glass transition temperature
$W_t$	Percentage weight gain
$W_{\infty }$	Saturated percentage weight gain
W ∞1	Saturated weight gain (Primary stage)
W ∞2	Saturated weight gain (Secondary stage)
α	Sound absorption coefficient (SAC)