FFs. Another thread of theoretical general aviation bolox. If you want to know your vs look at the plate under speed/vs for the published slope. OR
If you need to know your thrust setting in advance look at the qrh. or develop a memory
Even better as the bloke above alludes to learn to fly and not analyse., if not admit apptitude defeat and join a bank.
I cant believe how many threads are springing up having long winded discussions about stuff that wouldnt be an issue if there was some requirement for flying skill in this job these days.