Factores de conversión

Dr. Carlos Rubio Maya

Facultad de Ingeniería Mecánica, U.M.S.N.H.

Septiembre 2011

DIMENSION METRICO METRICO/INGLESAceleración 1m/s2 = 100 cm/s2 1m/s2 = 3.2808 ft/s2

1 ft/s2 = 0.3048m/s2

Area 1m2 = 104 cm2 = 106 mm2 = 10−6 km2 1m2 = 1550 in2 = 10.764 ft2

1 ft2 = 144 in2 = 0.09290304m2

Densidad 1 g/cm3 = 1 kg/L = 1000 kg/m3 1 g/cm3 = 62.428 lbm/ft3 = 0.036127 lbm/in3

1 lbm/in3 = 1728 lbm/ft3

1 kg/m3 = 0.062428 lbm/ft3

Energía 1 kJ = 1000 J = 1000N ·m = 1 kPa ·m3 1 kJ = 0.94782Btu1 kJ/kg = 1000m2/s2 1Btu = 1.055056 kJ1 kWh = 3600 kJ = 5.40395 psia · ft3 = 778.169 lbf · ft1 cal = 4.184 J 1Btu/lbm = 25, 037 ft2/s2 = 2.326 kJ/kg1 ITcal = 4.1868 J 1 kJ/kg = 0.430Btu/lbm1 Cal = 4.1868 kJ 1 kWh = 3412.14Btu

1 termia = 105 Btu = 1.055x105 kJ (G.N.)Fuerza 1N = 1 kg ·m/s2 = 105 dina 1N = 0.22481 lbf

1 kgf = 9.80665N 1 lbf = 32.174 lbm · ft/s2 = 4.44822NFlujo de calor 1W/cm2 = 104 W/m2 1W/m2 = 0.3171Btu/h · ft2Coe�ciente detransferenciade calor 1W/m2 ·◦ C = 1W/m2 ·K 1W/m2 ·◦ C = 0.17612Btu/h · ft2 ·◦ FLongitud 1m = 100 cm = 1000mm = 106 µm 1m = 39.370 in = 3.2808 ft = 1.0926 yd

1 km = 1000m 1 ft = 12 in = 0.3048m1milla = 5280 ft = 1.6093 km1 in = 2.54 cm

Masa 1 kg = 1000 g 1 kg = 2.2046226 lbm1 ton metrica = 1000 kg 1 lbm = 0.45359237 kg

1 onza = 28.3495 g1 slug = 32.174 lbm = 14.5939 kg1 ton corta = 2000 lbm = 907.1847 kg

Potencia 1W = 1 J/s 1 kW = 3412.14Btu/h1 kW = 1000W = 1.341 hp = 737.56 lbf · ft/s1 hp = 745.7 kW 1 hp = 550 lbf · ft/s = 0.7068Btu/s

= 42.41Btu/min = 2544.5Btu/h= 0.74570 kW1 hp caldera = 33, 475Btu/h1Btu/h = 1.055056 kJ/h1 ton de refrigeracion = 200Btu/min

Presión 1 Pa = 1N/m2 1 Pa = 1.4504x10−4 psia1 kPa = 103 Pa = 10−3 MPa = 0.020886 lbf/ft2

1 atm = 101.325 kPa = 1.01325 bars 1 psi = 144 lbf/ft2 = 6.894757 kPa= 760mmHg (0◦C) = 760 torr 1 atm = 14.696 psia = 29.92 in Hg (30◦F )= 1.03323 kgf/cm2 = 10.3323m c.a. 1 in Hg = 3.387 kPa1mmHg = 0.1333 kPa

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DIMENSION METRICO METRICO/INGLESCalor especí�co 1 kJ/kg ·◦ C = 1 kJ/kg ·K 1Btu/lbm ·◦ F = 4.168 kJ/kg ·◦ C

1Btu/lbmol ·R = 4.1868 kJ/kmol ·K1 kJ/kg ·◦ C = 0.23885Btu/lbm · F= 0.23885Btu/lbm ·R

Volumen especí�co 1m3/kg = 1000 L/kg = 1000 cm3/g 1m3/kg = 16.02 ft3/lbm1 ft3/lbm = 0.062428m3/kg

Temperatura T (K) = T (◦C) + 273.15 T (R) = T (◦F ) + 459.67 = 1.8T (K)∆T (K) = ∆T (◦C) T (◦F ) = 1.8 T (◦C) + 32

∆T (◦F ) = ∆T (R) = 1.8 ∆T (K)Conductividadtérmica 1W/m ·◦ C = 1W/m ·K 1W/m ·◦ C = 0.57782Btu/h · ft ·◦ FVelocidad 1m/s = 3.60 km/h 1m/s = 3.2808 ft/s = 2.237mi/h

1mi/h = 1.46667 ft/s1mi/h = 1.6093 km/h

Volumen 1m3 = 1000 L = 106 cm3 1m3 = 6.1024x104 in3 = 35.315 ft3

= 264.17 gal(US)1 US galon = 231 in3 = 3.7854 L1 fl onza = 29.5735 cm3 = 0.0295735 L1 US galon = 120 fl onzas

Flujovolumétrico 1m3/s = 60, 000 L/min = 106 cm3/s 1m3/s = 15, 850 gal/min (gpm) = 35.315 ft3/s

= 2118.9 ft3/min (cfm)Viscosidad 1 Poise(P ) = 1 g/cm · s = 0.1 kg/m · s 1 slug/ft · s = 47.88 kg/m · s

1 Pa · s = 1 kg/m · s 1 lbm/ft · s = 0.031081 lbf · s/ft2

Constantes físicas

Constante universal de los gases Ru = 8.31447 kJ/kmol ·K= 8.31447 kPa ·m3/kmol ·K= 0.0831447 bar ·m3/kmol ·K= 82.05 L · atm/kmol ·K= 1.9858Btu/lbmol ·R= 1545.37 ft · lbf/lbmol ·R= 10.73 psia · ft3/lbmol ·R

Aceleración de la gravedad estándar g = 9.80665m/s2

= 32.174 ft/s2

Presión atmosférica estándar 1 atm = 101.325 kPa= 1.01325 bar= 14.696 psia= 760mmHg (0◦C)= 29.9213 in Hg (32◦F )= 10.3323mH2O (4◦C)

Constante de Stefan-Boltzmann σ = 5.6704x10−8 W/m2 ·K4

= 0.1714x10−8 Btu/h · ft2 ·R4

Constante de Boltzmann k = 1.380650x10−23 J/KVelocidad de la luz en el vacío co = 2.9979x108 m/s

= 9.836x108 ft/sVelocidad del sonido en aire seco (0oC y 1 atm) c = 331.6m/s

= 1089 ft/sCalor de fusión del agua (1 atm) hif = 333.7 kJ/kg

= 143.5Btu/lbmEntalpía de vaporización del agua (1 atm) hfg = 2256.5 kJ/kg

= 970.12Btu/lbm

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