Getting Energy Straight Force -- Newton -- Mass times Acceleration ( F = MA ) Kilograms times Meters per Sec^2: (Kg x M) / S^2 1 newton = 10^5 dynes 1 pound-force ~= 4.5 newtons Work -- Joule -- Force times Distance ( W = FD ) (aka Energy) Newtons times Meters -- N x M: (Kg x M^2) / S^2 1 Joule = 10^7 ergs .74 foot-pounds 6.25x10^18 electron volts 1 BTU = 1 Kilo-joule Power -- Watt -- Work per Time ( P = W/S ) Joules per Second -- J/S: (Kg x M^2) / S^3 1 HP = 550 ft-lb/s = 745.7 watts 1 Kw = 1.34 HP 1 BTU/hour = .29 watts note: Watt = volt x ampere Volt = joule / columb 1 Columb -- amp-sec ~= 6.25 x 10^18 electron-second Watt-seconds -- volt x columb 1 Joule = 1 Watt-second 1 KwHr = 3.6 Mega-joule for extra credit: Pressure -- Pascal -- Force per Area ( P = F/A ) Newtons per Meter^2 -- N/M^2: Kg / (M x S^2) 1 pound/sqin (PSI) = 6.9 Kpascal 1 dyne/cm^2 = 10 Pascal(/M^2) Or more sussicintly: distance(d) time(t) mass(m) velocity(v) = d/t acceleration(A) = v/t = d/t^2 force (F) = Am = vm/t = dm/t^2 work(W) = Fd = Amd = vmd/t = d^2m/t^2 power(P) = W/t = Fd/t = Amd/t = vmd/t^2 = d^2m/t^3 In the SI system, there are seven fundamental units: kilogram -- mass meter -- length candela -- luminous intensity (weighted to eye), 1/683-watt / steradian second -- time ampere -- current flow, columb per second kelvin -- temperature (energy?) mole -- Avogadro's # elementary entities == 6.02214179 x 10^23