Talk:Newton-second

Compound units expressed with hyphen

Should compound units be expressed with "-" or not? I.e. should the article be as "newton-second" or "newton second". Benkeboy 21:34, 17 May 2006 (UTC)

Compound units and similar compound words are always expressed with hyphen. It is the product of force with time. —Centrx→talk • 00:41, 7 July 2006 (UTC)

Actually, both a space and a hyphen are permitted in both English and French. Check rule 5.2. Dger (talk) 16:20, 16 February 2011 (UTC)

Can be a little confusing for people with limited knowledge of the subject, not totally clear if Ns^-1 or Ns is intended. Rob3rtlaw (talk) 19:08, 9 January 2012 (UTC)

The abbreviation of newton-seconds could be N·s, N s, or N.s. Ns^-1 could be written N/s but that would be called newtons per second NOT newton-seconds—the former is rate of force development, the latter linear impulse of a force. Dger (talk) 02:37, 10 January 2012 (UTC)

According to ISO 80000-1:2009 "In the English language, the name of the product of two units is the concatenation of the two names, separated by a space." One example is given (newton metre) and no mention is made of permitting a hyphen. Dondervogel 2 (talk) 06:48, 17 May 2015 (UTC)

Untitled

Corrections Whoever set this up left off the unit of measure for the velocity of a size 5 futball, so I added that plus its SAE conversion (previously all it had was the conversion from the -- missing -- m/s to km/h). Darr247 (talk) 21:11, 9 February 2017 (UTC)

Or rather, switched it around from the "units (units km/h)" format it was in to the "units km/h (units)" format the rest of the page uses. Darr247 (talk) 21:16, 9 February 2017 (UTC)

Regarding my car and gun example changes on 2019-11-29

What jumped out at me was the mass of the "regular small car" (direct quote, prior to my edits) and "an SUV" (direct quote), they were both rather heavy. The SUV was very heavy, in fact. I know cars relatively well, and I could only think of two SUVs that were as heavy as the example, the Chevy Subaru and the Ford Expedition, both of which are notoriously large. The Ford Explorer, for example, has much lower mass. The "regular small car" was a bit heavy, similar to a mid-size sedan or large sedan in US terms, for example the Toyota Camry. It actually needs to be a Camry with the largest engine and one or two humans inside. That's a mid-size sedan, the Toyota Avalon passes the mark, but it is "large" in US car terms. I changed the masses to match the Honda Civic, which I called "a four-door car", and the Ford Explorer or Honda Pilot or a huge number of full-size SUVs, which I called "an SUV". I rounded both masses so that they cover the best-selling compact car or the best-selling SUV in the US and in the EU after you round up or down to two significant figures, plus or minus two humans in the vehicle, and from 2013 to 2019, because the best-selling SUVs shifted a lot in that time. I used compact cars so that the masses would be different, if you actually want the most popular "regular car" as in a three-box design and four doors, it will be close in mass to the SUV. The Toyota Prius (fuel-efficient hybrid) and the Toyota Rav-4 (small SUV) are both very popular in the US and within 5% by curb weight.

I might suggest making the cars go faster. 10 meters/second is a round number, but slow. 30 meters/second is also fairly round, and a respectable speed for a highway. 20 meters/second is a bit fast for city driving and definitely slow for a highway. 10 meters/second is just slow, cyclists often go faster than that. A few humans can run roughly that fast. It doesn't seem like a typical speed, unlike the other examples. I didn't speed up the cars because I can see that a prior edit slowed them down.

Then I saw three examples that involve bullets leaving guns. They were obviously initially added by someone who knows about guns but is not a native English speaker - the bullets all "launch" from the guns. Then they were edited to add leading zeroes to the calibers, which is frankly incorrect. I changed "round" to "bullet", because the portion with that momentum is only the bullet, although the case, powder, and bullet are technically a round when considered together.

"Bullet" is also more familiar as a term, and this is not an article about guns. And it is still technically correct, the propellant gases also have momentum, and the case also has momentum, and the three are no longer connected nor moving in the same direction.

I almost deleted the names of the cartridges (they are 9mm Parabellum, 5.56mm NATO, and .50 BMG), but I didn't for one main reason: I have no idea what mass a 9mm bullet is. The .50 BMG bullet seems very heavy at 50 grams, but that could easily be correct. I'm also fairly sure 9mm Parabellum bullets have a wide range of masses, but the 5.56mm NATO bullets may be standardized. The muzzle velocities look correct, especially the 5.56mm NATO, that cartridge is used in the main service rifle in many countries, and every large country in Europe that makes rifles makes a different rifle chambered for that round. The US originally used it in the M-16 rifle, but I think that isn't the service rifle anymore. I'm primarily interested in engineering and I know the M-16 was adopted by the US during the Vietnam War.

I almost deleted the .50 BMG example, and the original author called it a "rifle". The "BMG" stands for "Browning machine gun", and the original gun for that cartridge was very large. It has a rifled barrel, but calling it a "rifle" will give readers the wrong idea and may be incorrect. It is a machine gun. I was surprised to see that the .50 BMG round is used in hand-held firearms, like the Barrett M82, but the muzzle velocity now doesn't match. The listed velocity would match a belt-fed machine gun with a very long barrel.

I think the 9mm Parabellum and 5.56mm NATO examples are probably good. The 9mm round is extremely popular around the world with police. The 5.56mm NATO round is similarly popular with armies. I'm not sure how common machine guns are, or whether the .50 BMG cartridge has a large market share in machine guns. I would guess that the 7.62mm NATO cartridge has the largest market share for machine guns, and it is much smaller. I left it in largely because it provides contrast with the handgun and the rifle, just like I picked a smaller-end car and a larger-end SUV. Fluoborate (talk) 13:25, 29 November 2019 (UTC)

Edited .50 BMG to anti-material, more indicative of use. .50BMG was developed for use in the M2 machine gun, hence the name, but is now used in many other applications. Projectile weights are correct, on higher side of projectile weight though. I5-X600K (talk) 19:54, 12 March 2021 (UTC)

objection to name change

Where is the discussion that led to changing the perfectly good name we had before? Dondervogel 2 (talk) 06:21, 6 April 2020 (UTC)