Thank you! I followed your steps and found the final formula.I'm having a hard time deciphering your writing, but if there really are t4's and t5's in there, then I think I've got it.
It's just a couple lines of algebra.
Start with what you want -- t_rr. You have two options: Start with the second equation, which already has t_rr on the left, or solve the third equation for t_rr. Either will work, but the first seems more direct.
Write t5 in terms of S and t4.
Then write t4 in terms of what is in the first equation.
Then get rid of I_rr based on the third equation.
Now solve this for t_rr.
by Jake Hertz
by Jake Hertz
by Aaron Carman
by Jake Hertz