mechanical engineering - Pound-force (lbf) vs Pound-mass (lbm ...
2015年8月25日 · 1 pound mass is that mass that weighs one pound in 1 g gravity. For most practical cases, a pound mass and a pound weight define the same amount of stuff on the surface of the earth. To define a pound mass we rearrange Newton's law of F = mA to. m = F/A. then plug in the particulars to get pound mass: 1 pound mass = (1 pound force)/(32.174 ft/s²)
pound force and pound mass - Engineering Stack Exchange
2021年2月16日 · By example, an object with a mass of 5 lb $_m$ has a mass of 2.2680 kg regardless of where it sits (e.g. what planet). But this mass. exerts 5 lb $_f$ as its weight on earth; exerts 0.827 lb $_f$ as its weight on the moon with gravitation 5.32 ft/s $^2$ By inversion, an object that exerts 5 lb $_f$ as its weight on the moon has a mass of 30.2 ...
simulation - Where does weight mass conversion ratio '0.00259' …
2016年8月22日 · I think this is very fundamental question. I am wondering why 0.00259 is used as weight-mass conversion ratio, when inch/pound unit is used in Nastran.
fluid mechanics - Different Values for Different Calculations of ...
2022年4月19日 · In the Imperial system the mass unit is the slug [sl], and is derived from the pound-force by defining it as the mass that will accelerate at $1 ft/s^2$ when a $1 lb_f$ acts upon it. The density of water is $1.940 sl/ft^3$ at 39 °F (4 …
Understanding required torque for a motor lifting a weight
2015年5月14日 · 5 cm = 0.05 m. The gravitational force on your 450 g mass is 4.4 N as you say, so the torque just to keep up with gravity is (4.4 N)(0.05 m) = 0.22 Nm. However, that is the absolute minimum torque just to keep the system in steady state. It leaves nothing for actually accellerating the mass and for overcoming the inevitable friction.
Force at end of pivot beam, based on total mass and CG?
2023年6月13日 · A handle lever need to be balanced so it does not move by gravity or vertical acceleration. This handle moves ±90∘ from center (top position). Supported by ball bearing in center. The unit can bare...
Mass and weight of air in a room - Engineering Stack Exchange
A pound force is defined as the force required to accelerate a slug at 1 ft/s^2. The density of air is $\rho = 0.0724 \ lb_m/ft^3 = 0.0724/32.2 \ slugs/ft^3$ The weight of the air is $\rho V g = 0.0724/32.2 \ slugs/ft^3 \cdot32.2 ft/s^2\cdot 6000 ft^3 = 0.0724\cdot 6000 \ …
airflow - How do I convert cubic metres/feet per minute to a …
2016年5月17日 · The remaining problem is to convert kg to pounds. Kg is a unit of mass, and pounds is a unit of weight. The conversion depends on gravity. You didn't say if whether this is on the surface of the earth, on the internal space station, or somewhere else. I'll assume the surface of the earth where 1 kg of mass weighs about 2.2 pounds.
torque - Difference between winch pulling vs lifting capacity - how …
2022年9月26日 · Trying to figure out if a 4x4 winch that is rated to pull 3000lb (1360kg) could be used to hoist the 500kg keel on my trailer boat.
Could air-launched space planes reach escape velocities?
2015年2月7日 · M2 = start mass M1 = end mass g = gravitational constant (~~= 10 m/s/s) Call M2/M1 = mass ratio = MR. Using a modest by modern standards Isp of 300, to produce a delta-V of say 4000 m/S requires a MR of about 3.7 or end mass ~= 1/3.7 = 27% of total. So ABOUT 25% of the above 13,500 pounds could be delivered to lunar orbit =~ 3375 pounds = 1.5 tons
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