Hi everybody.
I wan't to input a number with the unit J/Kg * degrees cesius.
but when i add the celsius unit after i typed kg and ''*'' it becomes red.
anyone who knows how to input a specific heat unit?
Depends on the version. Only M14 fully supports Celsius units, but you'd need to look at the Insert Unit menu selection to see how to input it, as there are two similar units. For any version entering a "K" will always work, as specific is actually defined as J/(kg*K) in SI units.
Degree Celsius has been a long-standing annoyance in Mathcad, since it is sometimes used as a delta temperature, and is completely equivalent to a kelvin, while other times it's used as a psuedo-absolute unit, and is equivalent to the kelvin temperature minus 273.15K.
In M11, I use kelvins for all temperature related calculations; you just have to subtract 273.15K if you want Celsius temperature.