Your notation is extremely confusing. Equals signs denote equality. So, you are saying that 30*120 is equivalent to mm^{2}. I think what you mean is , so the units for are . What calculation are you saying is equivalent?
I have 7850 kg/m3
and its included in the following calculation
1,35*gk
where gk is = 30*120*7.85*10^-6 * 9,82
Another calculation i have seen writes 7,85 * 10^-1
30*120= mm˛
7.85*10^-6 = kg/mm^3
9,82= N/kg
the answer To equation 1.35*gk= 0,375 N/mm
what actually drives me crazy is That i dont know how
7850 kg/m3 becomes 7,85*10^-6 or *10^-1 and still gives same answer
could Someone explain To me thoroughly and show me how 7850 kg/m3 is converted in this case
thank you
You convert Kg/m^3 to Kg/mm^3 using the fact that there are 1000 mm per meter. Thus 1 meter = 1000 mm, and hence 1m/1000mm = 1. So you can multiply anything by 1m/1000mm and its just like multiplying by 1. Similarly, you can take the number 7.85x10^3 Kg/m^3, and multiply by 1^3 without changing its value:
I trust you see how the m^3 terms canceled out. Hope this helps. I have no idea where the 7.85 x 10^-1 comes from; how did that come up?