Weird Google thing.

[Wisnaeme]

Hi all,

I did a search for a battery last night and copy/pasted a term that wasn't formatted perfectly.
The search was : "12V/9Ah"
The result confused me.  Any idea what the hell it means?


(12 volts) / (9 ampere hours) = 0.00037037037 m2 kg s-4 A-2

[setq]

Looks like it tried to factor the units and gave up.

[hasithvm]

Hi all,

I did a search for a battery last night and copy/pasted a term that wasn't formatted perfectly.
The search was : "12V/9Ah"
The result confused me.  Any idea what the hell it means?


(12 volts) / (9 ampere hours) = 0.00037037037 m2 kg s-4 A-2

A volt (V) in SI base units (kg - kilogram, m - meter, s - second, A - ampere ) is a (kg *m²) / (s³ * A). Divide that by A*h (or multiply by 1/(A*h), which is (1/(3600*A*s)) and you get units of

kg *m² / (s⁴ * A²).



See: http://www.wolframalpha.com/input/?i=1+V%2F%281A*h%29

[Wisnaeme]

Yeah. Nope. I'm too old for this sht as I have no idea at all of what you talk. 

Thanks for the reply! 

[alanb]

Yeah. Nope. I'm too old for this sht as I have no idea at all of what you talk. 

Thanks for the reply! 

Its called Dimensional Analysis

https://en.wikipedia.org/wiki/Dimensional_analysis

[tszaboo]

#Some joke about a hot air balloon, programmers, perfectly good and absolutely useless answers.

[alsetalokin4017]

If you enter an arithmetical expression into the Google search window, it tries its best to evaluate the expression. It doesn't care what use you make of the answer! In this case it has answered your question correctly. If you think it's a joke... go ahead and laugh. If you are a physicist working on some new kind of antigravity thruster and you need this answer to get your Nobel prize... good for you. Google is like Honey Badger: it don't care.
 

[rdl]

If you enter an arithmetical expression into the Google search window, it tries its best to evaluate the expression.
...

This.

Google assumed you wanted the answer to a math problem. You can also enter conversions.
Try googling these:

1 dollar to euro

23.7 feet to meter

99C to F

There's probably other similar things it can do.

[matseng]

Google does a metric shitton of cool stuff.  For instance 10*10 in hex or 500 V * 3 A in KW
A lot of examples of calculations, conversions and constants here http://www.googleguide.com/help/calculator.html

[setq]

To be fair you can do all that fluff on a half decent HP/TI calculator.

[Rick Law]

I think Google is getting the arrogance Microsoft once was famous for.  Their people assume they are smarter than you.

So, when you are merely looking for a simple screw driver, they hand you a drill because in their collective minds, they think you should be using that.

Every auto-update, I shudder at what kinds of garbage are they stuffing down my pipes.

The once "do no evil" google is now to the point that they are the evil I avoid.  I am still using my flip phone because I don't want them to have my contact lists, my calendar, and whatever other info on my phone that I take offense to their having.

[T3sl4co1l]

Try adding "per farad^-1" on the end.  Or put 1/( ... ) around it, to get right-side-up farads.

Why you'd want to express a battery as a[n upside-down] capacitor, I don't quite know... though for what it's worth, the result is roughly representative of the capacitance equivalent of the battery.  (Charge equivalent, I think -- not energy: the battery contains much more energy, as its terminal voltage drops very slowly until depleted.)

Correspondingly, the energy contained in a battery is approximately V * Ah (== units of energy, which will default to J).

Tim

[rdl]

I think Google is getting the arrogance Microsoft once was famous for.  Their people assume they are smarter than you.

So, when you are merely looking for a simple screw driver, they hand you a drill because in their collective minds, they think you should be using that.

Every auto-update, I shudder at what kinds of garbage are they stuffing down my pipes.

The once "do no evil" google is now to the point that they are the evil I avoid.  I am still using my flip phone because I don't want them to have my contact lists, my calendar, and whatever other info on my phone that I take offense to their having.

I use a Gophone. Nothing on it but a few numbers. Only use it for voice calls.

An individual internet user actually has a fair amount of control over what Google, Facebook, and other external sites can do/see. If you don't mind making the effort and a bit of inconvenience.

What's getting really scary are the ISPs, such as AT&T, Comcast, etc. Those guys are not confined to only what passes through your browser. The possibility exists to receive advertising, based on internet sites you visit, in your home mailbox.

[Alexei.Polkhanov]

Not "per" but "in" works:
https://www.google.ca/search?q=10*10+in+hex&oq=10*10+in+hex&aqs=chrome..69i57j69i64.279j0j8&sourceid=chrome&ie=UTF-8#q=12+Volt+%2F+9+Ampere+hour+in+farad%5E-1

[suicidaleggroll]

It's just solving the math problem you [didn't realize you] gave it and converting to base SI units.

Same thing happens if you type in any other math problem with mixed units:
8volts/6ohms = 1.33 amps
1000 furlong/fortnight = 0.372 mph

[edy]

I wonder if it will calculate Star Trek or other Sci Fi units. 

[timb]

I wonder if it will calculate Star Trek or other Sci Fi units. 

6.12 jigawatts * 12 cochrans = x (in warp units)

[metrologist]

A volt (V) in SI base units (kg - kilogram, m - meter, s - second, A - ampere ) is a (kg *m²) / (s³ * A).

This reminded me of a question I once asked, if there was an absolute standard voltage.

I was thinking that all of those quantities had well defined metrology "standards" which are absolute (as opposed to relative).

And then I found this: https://www.ebmag.com/blog/the-ampere-is-a-sort-of-metrological-embarrassment-18991

[hasithvm]

A volt (V) in SI base units (kg - kilogram, m - meter, s - second, A - ampere ) is a (kg *m²) / (s³ * A).

This reminded me of a question I once asked, if there was an absolute standard voltage.

I was thinking that all of those quantities had well defined metrology "standards" which are absolute (as opposed to relative).

And then I found this: https://www.ebmag.com/blog/the-ampere-is-a-sort-of-metrological-embarrassment-18991

The ampere has always seemed a little hand-wavey to me....and now I know why!