jinsuk Lee wrote:
that's okay.
Anyway, I wonder how to reduce calculating time in my work.
That would need a quite good understanding of whats happening in your sheet and what should be calculated.
You have a lot of solve blocks which are called very (too) often and maybe even are nested (one block may call the other - haven't looked that close, though.
You redefine quite a lot of functions in your sheet, using the same name and so overwriting the previous function. Not sure if this is as it should be. For instance CD and CL are defined twice in a very similar way. You should know why but I am confused, especially as later calculation (which are vital for the function P()) use both the old (via function chd()) and the new (via function ct() and others) definition. Hard to image that that should be as you intend.
So I guess that unless you redesign the whole sheet from scratch it would be hard to speed it up or maybe correct it.
Unless you consider a complete redesign you may just implement slight improvements. For instance you can cut the calculation time for the numeric integration (functon MO()) approximately in half when you precalculate the values of m() as each is calculated twice now.
No quantum leap, but constant drippingwears away the rock.
Concerning your original question I wonder why you don't do in the solve block the very same which you did above? Simply replace 3 m/s by v and it should work. Or are you searching something else?
BTW, the pic is a fake as I wasn't willing to wait for the calculations to finish, but I am pretty sure that it should work OK that way if you dare to wait until calculation ends.