各种单位制常用单位换算
长度 1 m = 3.2808 ft = 39.37 in
1 ft = 1
2 in =0.3408 m
1 in = 2.54 cm
1 mile = 5280 ft = 1.6093×103 m
质量 1 kg = 1000 g = 2.2046 lb =6.852×10-2 slug
1 lb = 0.45359 kg = 3.10801×10-
2 slug
1 slug = 1 lbf·s2/ft = 32.174 lb = 14.594 kg
时间 1 h = 3600 s = 60 min
1 ms = 10-
2 s
1 us = 10-6 s
力 1 N = 1 kg·m/s2 = 0.102 kgf = 0.2248 lbf
1 dyn = 1 g·cm/s
2 =10-5 N
1 lbf = 4.448×105 dyn = 4.448 N = 0.4536 kgf
1 kgf = 9.8 N =2.2046 lbf = 9.8×105 dyn = 9.8 kg·m/s2
能量 1 J = 1 kg·m2/s2 = 0.102 kgf·m = 0.2389×10-3 kcal = 1 N·m
1 Btu = 778.16 ft·lbf = 25
2 cal =1055.0 J 1KW=3340BTU/H
1 kcal = 4186 J = 427.
2 kgf·m = 3.09 ft·lbf
1 ft·lbf = 1.3558 J = 3.24×10-4 kcal = 0.1383 kgf·m
1 erg = 1 g·cm2/s
2 = 10-7 J
1 eV = 1.602×10-19 J
1 kJ = 0.9478 Btu = 0.2388 kacl
功率 1 W = 1 kg·m2/s2 = 1 J/s = 0.9478 Btu/s = 0.2388 kcal/s
1 Kw = 1000W = 341
2 Btu/h = 859.9 kcal/h = 1 kJ/s
1 hp = 0.746 Kw = 2545 Btu/h = 550 ft·lbf/s
1 马力=75 kgf·m/s = 735.5 W = 2509 Btu/h = 542.3 ft·lbf/s
压力 1 atm = 760 mmHg = 101325 N/m2 = 1.0333 kgf/cm2 = 14.6959 lbf/in2 = 1.03323 at
1 bar = 105 N/m
2 = 1.0197 kgf/cm2 = 750.06 mmHg = 14.5038 lbf/in2
1 kgf/cm
2 = 735.6 mmHg = 9.80665×104 N/m2 =14.223
3 lbf/in2
1 Pa =1 N/m2= 10-5bar = 750.06×10-5mmHg =10.1974×10-5mH2O = 1.01972×10-5at
=0.98692×10-5atm
1 mmHg = 1.3595×10-3 kgf/cm
2 = 0.01934 lbf/in2 = 1 Torr =133.
3 Pa
1 mmH2O = 1 kgf/m
2 = 9.81 Pa
比热容 1 kJ/(kg·K) = 0.23885 kcal/(kg·K) = 0.2388 Btu/(lb·°R)
1 kcal/(kg·K) = 4.1868 kJ/(kg·K) = 1 Btu/(lb·°R)
1 Btu/(lb·°R) = 4.1868 kJ/(kg·K) = 1 kcal/(kg·K)
比体积 1 m3/kg = 16.0185 ft3/lb
1 ft3/lb = 0.062428 m3/kg
温度t/℃=T/K-273.15
t F =9t/(5℃)+32 = 9T/(5K)-459.67
1 °R=(5/9)K
常用物理常数
阿伏加德罗数N A = 6.022×1023 mol-1
玻尔兹曼常数k = 1.380×10-23 J/K
普朗克常数h = 6.626×10-34 J·s
摩尔气体常数R = 8.314510 J/(mol·K)
= 1.9858 Btu/(lbmol·°R)
= 1.9858 cal/(mol·K)
1 kg干空气的气体常数R a = 287.05 J/(kg·K)
= 29.23 kgf·m/(kg·K)
1 kg水蒸气的气体常数R H2O = 461.5 J/(kg·K)
重力加速度g = 9.80665 m/s2
水的比热容c= 4.1868 kJ/(kg·K)
1 物理大气压 1 atm = 760 mm Hg = 101.325 kPa
