Comments on: Factoid https://habitablezone.com/2015/04/01/factoid/ Thu, 09 Apr 2026 15:15:13 -0700 hourly 1 http://wordpress.org/?v=3.3.1 By: bowser https://habitablezone.com/2015/04/01/factoid/#comment-32410 bowser Sat, 04 Apr 2015 23:52:39 +0000 https://www.habitablezone.com/?p=49285#comment-32410 Trying to find the Youtube documentary which had the fellow from either Boeing or General Electric describing the engines. I tend to think you are correct. HOWEVER, yer messing with General Electric. Ask your wife to start your car. Trying to find the Youtube documentary which had the fellow from either Boeing or General Electric describing the engines. I tend to think you are correct.

HOWEVER, yer messing with General Electric. Ask your wife to start your car.

]]> By: ER https://habitablezone.com/2015/04/01/factoid/#comment-32408 ER Sat, 04 Apr 2015 03:52:56 +0000 https://www.habitablezone.com/?p=49285#comment-32408 which can be abbreviated either lb or lbf, to indicate they are pounds of force, not mass. In English units, the unit of mass is the Slug. Force = mass x acceleration so a mass of 1 slug in earths gravitational acceleration (32 ft/sec^2) exerts a force (or weight) of 32 pounds. In metric units, a mass of 1 kg in earth's gravitational field (9.8 m/s^2) results in a weight of 9.8 N. 1 Pound (lbf) = 4.448 N. I hate to be picky picky, but when working in English units, its really easy to get turned around if you forget that mass and weight are not the same thing. Its confusing, because we tend to think of something that weighs a pound force (like a pint of water) as massing a pound, which is not strictly true (it masses 1/32 slug). So we have terms for pound-force (lbf) and pound mass (lbm), which can be very confusing. In metric, a liter of water (about a quart) masses a kilogram, but it <em>weighs</em> 9.8 Newtons. which can be abbreviated either lb or lbf, to indicate they are pounds of force, not mass. In English units, the unit of mass is the Slug. Force = mass x acceleration so a mass of 1 slug in earths gravitational acceleration (32 ft/sec^2) exerts a force (or weight) of 32 pounds.

In metric units, a mass of 1 kg in earth’s gravitational field (9.8 m/s^2) results in a weight of 9.8 N.

1 Pound (lbf) = 4.448 N.

I hate to be picky picky, but when working in English units, its really easy to get turned around if you forget that mass and weight are not the same thing.

Its confusing, because we tend to think of something that weighs a pound force (like a pint of water) as massing a pound, which is not strictly true (it masses 1/32 slug). So we have terms for pound-force (lbf) and pound mass (lbm), which can be very confusing. In metric, a liter of water (about a quart) masses a kilogram, but it weighs 9.8 Newtons.

]]> By: RobVG https://habitablezone.com/2015/04/01/factoid/#comment-32407 RobVG Sat, 04 Apr 2015 02:48:16 +0000 https://www.habitablezone.com/?p=49285#comment-32407 B52 Pratt & Whitney TF33s (total thrust 8 × 17,000 lb) = 136,000 lb <a href="http://en.wikipedia.org/wiki/Boeing_B-52_Stratofortress#Engines" rel="nofollow">Here</a> A 66,500 lbf (296 kN) thrust version (GEnx-2B67) will be used on the 747-8 <a href="http://en.wikipedia.org/wiki/General_Electric_GEnx#Design_and_development" rel="nofollow">Here</a> Not sure what the difference might be between "lb" and "lbf". B52 Pratt & Whitney TF33s (total thrust 8 × 17,000 lb) = 136,000 lb

Here

A 66,500 lbf (296 kN) thrust version (GEnx-2B67) will be used on the 747-8

Here

Not sure what the difference might be between “lb” and “lbf”.

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