Recent content by petreza

Ha-ha, so true about the hammock. Haven't even tried it - I know the answer subconsciously. In my defense, geometric representations often give additional insight than just mechanical algebraic calculation but unfortunately in this case the geometric representation might be considered convoluted.

I am sorry I didn't make my point more clear. I was talking about my imaginary friend here - Sun' - note the prime symbol at the end. It is a point like sun with the same mass M as the Sun and that always stays in the direction of FG+d but just a little bit closer to the particle to account for...

At each instant FG+d points toward the center of Sun' which is counter-parallel to R' (position vector relative to Sun' ) - it is the same situation as with the regular Sun and the particle but without the drag force - circular orbit (which I chose as a starting orbit for simplicity) BTW, I am...

I was hoping for a simple explanation in terms of basic "properties" - forces, distances and mass. For example we can say that without the drag force, R (as a position vector) is always counter-parallel to FG so the particle stays in the same circular orbit with the same V. On the other hand...

Let me be more specific in my terms here - I am concerned about the SPEED of the particle - velocity always changes because its direction always changes - with or without the drag force. I don't think you can say that the drag force has no effect on the SPEED of the particle because without the...

I understand it in simple one dimensional motion. Force acts against velocity, velocity is reduced, energy (kinetic) is reduced. Here, force acts against velocity, velocity is increased, kinetic energy is increased yet total energy is decreased because reasons. I suspect it has to do with...

Of course, I only meant it as a (pre-) intuitive view of the problem, hence the "At first glance" The initial (wrong) view could be like this: higher orbits have shower velocities; the force acts opposite the velocity and so must reduce it; consequently the particle must be moving to a higher...

Hello, Orbital mechanics is a bit of mystery to me. Let us have a particle with mass m orbiting the Sun (with mass M)in a circular orbit with radius R. The velocity vector V is always tangential to the orbit. Let us also have a weak, constant ("drag") force Fd that is always pointing in the...