PeroK's latest activity

The problem that has arisen here is that if ##\frac{dm}{dt}## is positive for a rocket losing mass, then all the theorems of the...

You have no choice with the derivative: it's positive when a quantity is increasing. You have chosen the opposite convention for...

I suspect the problem is that, because you've taken ##\Delta m## to be positive when the rocket is losing mass, you have...

Okay, the problem must be with your solution to the differential equation.

PS if you want to take ##v_{gas}## as the velocity of the gas relative to the rocket, then you need ##v + v_{gas}## in that equation...

Let's look at this equation in the rest frame of the rocket (##v = 0##). We have: $$(m-\Delta m)(\Delta v)+\Delta m(0-v_{gas})=0$$Which...

I suspect that ##v_{gas}## is the problem. If you use velocities rather than speeds, then you can use a single equation. Moreover, the...

PS try ##v =0## and see what happens.

I can look at this later. In the meantime, what are the possible values of ##v## and ##v_{gas}##?

Now we have reached the nub of the matter. Unless we use your preferred terminolgy and look at physics your preferred way, and share...

And who are we to argue with the late Arnold B Arons?

The only bending over backwards is when uttering the phrase "action-reaction" instead of "Third-Law pair of forces". The former is a...

As an example, imagine we have a financial spreadsheet. Let's say column A is the starting balance, column B is a deposit and column C...

You can choose whichever convention you like. You just have to be careful to be clear about the convention you use and be careful to...

@Green dwarf did we not go through all of this with you ten years ago...