Glossary

Dyne:
the force required to accelerate 1 g of mass at 1 cm per second; 1 dyne = 10^{ 5} newtons 
Energy:
the ability or capacity to do work; in physics, essentially synonymous
with work 
Energy density:
energy per unit area; in lasers, units = joules/cm^{2} 
Erg:
a dynecentimeter; the work or energy of 1 dyne applied over a distance
of 1 cm; a unit of energy; 1 erg = 10^{ 7} joules 
Joule:
a newtonmeter; the work or energy of 1 newton applied over a distance
of 1 meter; a unit of energy; 1 joule = 10^{7} ergs 
Nanosecond:
a billionth (10^{ 9}) of a second 
Newton:
the force needed to accelerate 1 kg of mass at 1 meter per second per
second; 1 newton = 10^{5} dynes 
Picosecond:
a trillionth (10^{ 12}) of a second 
Power:
energy per unit of time; how fast energy is produced or transferred 
Power density:
power per unit area; in lasers, units = watts/cm^{2} 
Watt:
one joule per second; a unit of power 
Work:
“force times distance”; the product of a force and the distance
through which it produces displacement; synonymous with energy 