Hi, i assign 460 GWh to a E variable (Giga Watt hours).
Then I want to see it in kWh (or MWh).
Trying to write E='MWh results as on picture (units are not recalculated by prefixes).
Is it normal? Do I have to add my own calculation among prefixes to obtain proper recalculation?

Wrote

Is it normal? Do I have to add my own calculation among prefixes to obtain proper recalculation?

Yes, units prefixes are built-in (a variable must be declared in units.xml to accept the proper multipliers... so f.e. you can't have automatically gigakelvin or megaseconds)

SI standard



commercial/practical user-defined

Wrote

Yes, units prefixes are built-in (a variable must be declared in units.xml to accept the proper multipliers...

Interesting but rather confusing.
What is MW h
In lot of maths MW h is implicit of MW*h
Rather not same MW/h

Wrote

In lot of maths MW hr is implicit of MW*hr
Rather not same MW/hr

I guess it is possible to make it MW/hr

Wrote

In lot of maths MW h is implicit of MW*h
Rather not same MW/h

Two very different things [W*h]=[J] while [W/h]=[J/s^2]

However, yes, can be done even this (CTRL+K to add the backslash):

Thank you Davide. I just realized that my unit is not a standard unit but multiplication of two. I found it out when tried to convert my results to Joules (J). So you're right, it is enough to use kW*h instead of kWh. I buy it.

Btw. unit like kW/hr and W/s (Watts per time) are rather nonsense as W is already given in a time span (J/s).

Wrote

Btw. unit like kW/hr and W/s (Watts per time) are rather nonsense as W is already given in a time span (J/s).

Hi "M". Just not so fast. J/s^2 can be seen as the power acceleration, like the normal "acceleration", meter by second square. It could be practical in an electrical circuit for study the variation of p(t)=v(t)*i(t) (in lowercase, which means instant values). Usual electrical protections only study the "R by I square curve" and how the current increase in time (and remember that i=dq/dt), but one must to remember that Ohm's law isn't a "true" law: it's just a practical rule, which works only ... if it works, but isn't a natural principle, like Newton's laws.

Best regards.

Alvaro.

A while ago I requested Engineering Exponents/Notation.

https://en.smath.info/forum/yaf_postst374_Engineering-format-for-displaying-results.aspx

You would probably find that would meet your needs also.

Even of the exponents were coerced to 3s, it would probably help - I personally find it much easier when the exponents are in 3's, even if the prefixes aren't used