The Complete Book of Spaceflight: From Apollo 1 to Zero Gravity

4 How to Use This Book
Energy
1 joule (J) = 9.48 ×10 −4 British thermal unit (Btu)
1 electron-volt (eV) = 1.60 ×10 −19 J
1 GeV = 10 3 MeV = 10 6 keV = 10 9 eV
Note: Electron-volts are convenient units for measuring
the energies of particles and electromagnetic radiation. In
the case of electromagnetic radiation, it is customary to
measure longer-wavelength types in terms of their wavelength
(in units of cm, µm, etc.) and shorter-wavelength
types, especially X-rays and gamma-rays in terms of their
energy (in units of keV, MeV, etc.). The wavelength associated
with electromagnetic waves of energy 1 keV is
0.124 nm.
Force
1 newton (N) = 0.22 pounds-force (lbf) = 0.102 kilograms-force
(kgf)
1 kilonewton (kN) = 1,000 N
Power
1 watt (W) = 0.74 ft-lbf/s = 0.0013 horsepower (hp)
1 kilowatt (kW) = 1,000 W
Temperature
C = 5 ⁄9(F − 32)
F = 9 ⁄5C + 32