Appendix-D

Some Conversion Factors

Work, Energy, Heat Power

\(1~\mathrm{W}=1~\mathrm{J/s}\)

\(1~\mathrm{hp}=746~\mathrm{W}=550~\mathrm{ft}\cdot\mathrm{lb/s}\)

\(1~\mathrm{Btu/h}=0.293~\mathrm{W}\)

Angle

\(1~\mathrm{rad}=57.3^{\circ}=180^{\circ}/\pi\)

\(1^{\circ}=0.01745~\mathrm{rad}=\pi/180~\mathrm{rad}\)

\(1~\mathrm{revolution}=360^{\circ}=2\pi~\mathrm{rad}\)

\(1~\mathrm{rev/min}~(\mathrm{rpm})=0.1047~\mathrm{rad/s}\)

Mass and Density

\(1 ~kg = 1000 ~g = 6.02 \times 10^{26} ~u\)

\(1 ~slug = 14.59 ~kg\)

\(1 ~u = 1.661 \times 10{–27} ~kg\)

\(1~ kg/m^3 = 10^{–3} ~g/cm^3\)

Length and Volume

\(1 ~m = 100 ~cm = 39.4 ~in. = 3.28 ~ft\)

\(1 mi = 1.61 km = 5280 ft\)

\(1 ~in.= 2.54 ~cm\)

\(1 ~nm = 10^{–9} ~m = 10~ Å\)

\(1 ~pm = 10^{–12} ~m = 1000 ~fm\)

\(1 ~light-year = 9.461 \times 10^{15}~m\)

\(1 ~m^3 = 1000~ L = 35.3 ~ft^3 = 264 ~gal\)

Time

\(1 ~d = 86 400~ s\)

\(1 ~y = 365 ~d = 3.16 \times 10^7 ~s\)

Speed

\(1 ~m/s = 3.28 ~ft/s = 2.24 ~mi/h\)

\(1 ~km/h = 0.621 ~mi/h = 0.278 ~m/s\)

Force and Pressure

\(1 ~N = 10^5 ~dyne = 0.225 ~lb\)

\(1 ~lb = 4.45 ~N\)

\(1 ~ton = 2000 ~lb\)

\(1 ~Pa = 1 ~N/m^2= 10 ~dyne/cm^2\)

= \(1.45 = 10^{–4} ~lb/in.^2\)

\(1 ~atm = 1.01 = 10^5 ~Pa = 14.7 ~lb/in.^2\)

= \(76.0 ~cm Hg\)