arXiv subjects

Adel Alameh

Publications and source records attributed to Adel Alameh.

3 recordsLinked to original sources

arXiv2024

Rocket motion

The motion of rockets is part of the study devoted to the motion of variable mass systems. Notably those in which the mass leaves permanently the considered system. Rockets are propelled forward by the reaction force produced by the hot exhausted gases ejected from their tales in the rearward direction. Thus their motion should not violate Newton's third principle of the equality of action and reaction forces during the exhaustion process. Nor should it violate Newton's second law of motion judged by inertial observers. However a close examination of the study of the motion of rockets in a major part of physics textbooks, if not all reveals erroneous determination of the expression of the thrust force that pushes the rocket in the forward direction. The false expression of the thrust force entails a bad effect on obtaining the right differential equation that governs the motion of rockets. This trap induced some prominent physics authors to pretend the in applicability of Newton's second law in such particular cases. Not only that, but they also modified Newton's second law in order to fit their purposes of obtaining the right differential equation, historically known under the name Tsiolkovsky rocket equation. The object of this paper is to give the true expression of the thrust force and to write the differential equation of motion of rockets without any necessity of modification of the classical laws. The paper also delves into the expression of the change of velocity of rockets, and proves that their motion is uniformly accelerated in the early stages of liftoff from the ground at condition of constant velocity of expulsion of hot gases from their nozzles.

physics.class-ph↗

arXiv2022

Resonance curves are perfect circles

The ability to approach a physical phenomenon and grasp its major importance is a remarkable quality of understanding. This paper presents a rather elegant and novel way of looking at the resonance phenomenon, which among others shares a common conceptual basis in various fields of physics. For the sake of simplicity, the discussion will be restricted to the case of electric current resonance in series RLC circuits. The mathematics of electric resonance is thus meticulously extended to the extent that it ultimately unravels an invaluable relationship between the current at a certain driving frequency and that at the resonance frequency. Much further it gives rise to an elaborate correlation between any two driving frequencies that give the same current. Arising from the previously mentioned relations, a new technique is devised, a simple geometrical construction, that without running into tedious calculations, allows the computation of the phase difference between the current and the impressed voltage at any given frequency. Not to mention another geometric utility, that is miraculously constructed to correlate any frequency with its corresponding ``conjugate'' one, that allows the same current in the circuit.

physics.class-ph↗

arXiv2021

Yet another approach to the inverse square law and to the circular character of the hodograph of Kepler orbits

The law of centripetal force governing the motion of celestial bodies in eccentric conic sections, has been established and thoroughly investigated by Sir Isaac Newton in his Principia Mathematica. Yet its profound implications on the understanding of such motions is still evolving. In a paper to the royal academy of science, Sir Willian Hamilton demonstrated that this law underlies the circular character of hodographs for Kepler orbits. A fact which was the object of ulterior research and exploration by Richard Feynman and many other authors [1]. In effect, a minute examination of the geometry of elliptic trajectories, reveals interesting geometric properties and relations, altogether, combined with the law of conservation of angular momentum lead eventually, and without any recourse to dealing with differential equations, to the appearance of the equation of the trajectory and to the derivation of the equation of its corresponding hodograph. On this respect, and for the sake of founding the approach on solid basis, I devised two mathematical theorems; one concerning the existence of geometric means, and the other is related to establishing the parametric equation of an off-center circle, altogether compounded with other simple arguments ultimately give rise to the inverse square law of force that governs the motion of bodies in elliptic trajectories, as well as to the equation of their inherent circular hodographs.

physics.hist-ph↗