One thing I've noticed upon reading some of these calculations for speed, thrust, weight, and power is that they are neglecting the friction robbing effect of air resistance making their solutions questionable at speeds over 60mph and wildly invalid at speeds anywhere over 100! I've seen several posts mostly on other threads predict speeds based on power at over 200mph without ever considering air resistance. Converting weight/thrust ratios times velocity and other tricks are also invalid.

Ratio's, formulae, and such are often very convenient but designed to only work under a very narrow and specific set of conditions to make the calculations less cumbersome. It gets misused (abused) when someone applies this simplification in a much different context. Other people read this and validate it as reasonable and the error is taken up as a fundamental truth. I hope we can get back to some fundamental physics and quite using tricks.