#engineering Some important units to memorize | Quantity | unit 1 (SI) | unit 2 | unit 3 | comments | | ------------------------- | ----------- | ---------------------- | ------------------------------------ | ----------------------------------------------- | | Pressure | 1 bar | 100 kPa | 14.5 psi | | | Energy | 1055 | 1 BTU | 778.169 ft-lbf | | | Power | 1 Watt | 3.412142 BTU/hr | 1/1055 BTU/s | 0.73756 ft-lbf/s | | Thermal Conductivity | 1 W/m-K | 0.5776 BTU/ft-hr-F | | | | Conductance | 1 W/m^2K | 0.1761 BTU/ft^2-hr | 3.397e-7 BTU/s-in^2-F | 1 Btu/hr-ft^2 = 5.678 W/m^2K | | Length | 1 m | 3.281 ft | 39.37 in | | | Temperature | 20 C | (20 * 9/5) + 32 = 68 F | | | | Temperature rise | 1 C | 1.8 F | | | | Energy | 1054.35 J | 1 Btu | | BTU is energy req. to raise 1lbm of water by 1F | | Energy | | 1 BTU | 778.169 ft-lbf | | | Mass | 1 kg | 2.2046 lbm | 0.0685218 slug (divide lbm by 32.17) | | | Force | 1 N | 0.2248 lbf | | 1 lbf = 4.448 N | | Heat Transfer Coefficient | 1 W/m^2K | 0.1761 BTU/ft^2-hr-°F | | 1 Btu/hr-ft^2 = 5.678 W/m^2K | | Gas constant for air | 287 J/kg-K | 53.3523 ft-lbf/lbm-°R | 1716.46 ft-lbf/slug-°R | | ## 1. Lbf and Lbm $1 lbf = 32.17 lbm \frac{ft}{s^2}$ or $1lbm = \frac{1}{32.17}\frac{lbf.s^2}{ft}$