How to Convert One Green Photon Into Two Locomotives of Momentum

The physics of photon momentum are straightforward mathematically but can produce surprisingly counterintuitive outcomes. A few simple calculations show how a single photon of green light can, in principle, impart two locomotive engines’ worth of momentum without violating energy conservation. The calculation is one example of why quantum mechanics needs better accounting of linear momentum.

The development of electronic teaching materials on linear impulse and linear momentum to improve students’ scientific literacy

Students’ low scientific literacy competence and the unavailability of electronic teaching materials that match scientific literacy indicators that can be used in online learning encourage researchers to develop electronic teaching materials to improve students’ scientific literacy. This research aims to produce and describe the appropriateness of electronic teaching materials used in the learning process to enhance scientific literacy. The electronic teaching materials developed are based on scientific literacy indicators, namely explaining scientific phenomena, interpreting data and providing scientific evidence, designing and evaluating scientific investigations. The type of research used is research and development of the ADDIE model. The appropriateness of electronic teaching materials in terms of validity, practicality, and effectiveness. Research data was obtained from validation sheets given to three validators, student response questionnaires and learning outcomes tests. The data were analyzed by validity test, practicality test, and effectiveness test using N-gain score. The results showed that: 1) the validity of teaching materials obtained a score of 3.52 in the very high category, 2) the practicality of electronic teaching materials based on student response questionnaires obtained a percentage of 80.81% in the practical category, 3) the effectiveness of electronic teaching materials obtained a score of 0.44 in the medium category and the students’ scientific literacy ability 44.11% in the medium category. Based on the results of the study, impulse and linear momentum electronic teaching materials have been produced to improve students’ scientific literacy that is appropriate for use in the learning process. This research has implications, namely increasing students’ scientific literacy, especially on impulse and linear momentum material.

The relativistic feature of Hydrogen-like atoms in Heisenberg picture

The relativistic behavior of Hydrogen-like atoms (HLAs) is investigated in Heisenberg picture for the first time. The relativistic vibrational Hamiltonian (RVH) is first defined as a power series of harmonic oscillator Hamiltonian by using the relativistic energy eigenvalue . By applying the first-order RVH (proportional to ) to Heisenberg equation, a pair of coupled equations is turned out for the motion of electron position and its relativistic linear momentum. A simple comparison of the first-order relativistic and nonrelativistic equations reveals this reality that the natural (fundamental) frequency of electron oscillation (like entropy) is slowly raised by increasing the atomic number. The second-order RVH (proportional to ) have then been implemented to determine an exact expression for the electron relativistic frequency in the different atomic energy levels. In general, the physical role of RVH is fundamental because it not only specifies the temporal relativistic variations of position, velocity, and linear momentum of oscillating electron, but also identifies the corresponding relativistic potential, kinetic, and mechanical energies. The results will finally be testified by demonstrating the energy conservation.

On Reactive Force in Thin Unclosed Conductor and Displacement Current

The linear momentum density carried by electromagnetic fields creates the hidden force acting on the displacement current between ends of an unclosed conductor with alternative electric current. This force compensates the self-force exerted by the unclosed conductor with zero thin. The magnetic field produced by displacement current does not contribute to the force acting on the conductor. The unclosed conductor can move under action of the self-force. At small heights of cylindrical open conductor, the reactive force equivalent to the self-force becomes very large

Removal of instabilities of the higher derivative theories in the light of antilinearity

Theories with higher derivatives involve linear instabilities in the Hamiltonian commonly known as Ostrogradski ghosts and can be viewed as a very serious problem during quantization. To cure this, we have considered the properties of antilinearity that can be found inherently in the non-Hermitian Hamiltonians. Owing to the existence of antilinearity, we can construct an operator, called the V-operator, which acts as an intertwining operator between the Hamiltonian and its Hermitian conjugate. We have used this V-operator to remove the linear momentum term from the higher derivative Hamiltonian by making it non-Hermitian in the first place via an isospectral similarity transformation. The final form of the Hamiltonian is free from the Ostrogradski ghosts under some restriction on the mass term.

Analisis Perubahan Momentum Tubuh Bagian Atas Pada Saat Pukulan Tennis One-Handed Backhand Drive

Tujuan dari penelitian ini adalah menganalisis perpindahan linear dan angular momentum dari gerak tubuh bagian atas (upper extrimity) sampai perkenaan bola dengan raket pada saat melakukan pukulan backhand drive dengan satu tangan pada permainan tenis. Pukulan backhand drive adalah salah satu teknik yang paling sering digunakan dalam bermain tenis. Sangat sedikit penelitian yang menganalisis kajian terkait transfer linear momentum dan momentum rotasi dari gerak upper extrimity sampai perkenaan bola dengan raket pada saat melakukan pukulan backhand drive dengan satu tangan. Subjek dalam penelitian ini adalah pemain tenis putra yang berjumlah 12 orang (rata-rata ± SD; usia 27 ± 3.7 tahun, tinggi batang tubuh 169 ± 7.4 cm, berat batang tubuh 71.5 ± 8.3 kg). Metode yang digunakan adalah deskriptif dengan pendekatan kualitatif. Hasil penelitian ini menunjukan bahwa segmen tangan berkontribusi signifikan terhadap perubahan linear momentum (leading dan vertical direction) dan angular momentum (supination). Kesimpulan hasil penelitian ini adalah bahwa pemahaman tentang perubahan gerak kinetika, momentum dan force sangat penting dipahami pemain dan pelatih dalam upaya meningkatkan performa kualitas pukulan backhand drive dalam permainan tenis.

Lifshitz hydrodynamics at generic z from a moving black brane

A Lifshitz black brane at generic dynamical critical exponent z > 1, with non-zero linear momentum along the boundary, provides a holographic dual description of a non-equilibrium steady state in a quantum critical fluid, with Lifshitz scale invariance but without boost symmetry. We consider moving Lifshitz branes in Einstein-Maxwell-Dilaton gravity and obtain the non-relativistic stress tensor complex of the dual field theory via a suitable holographic renormalisation procedure. The resulting black brane hydrodynamics and thermodynamics are a concrete holographic realization of a Lifshitz perfect fluid with a generic dynamical critical exponent.