May 5th, 2021

лошадь, диаграмма, Фейнман

Одностраничная заметка о марсианском вертолете с численными оценками

Rotorcraft RPM on Mars:
Philip Blanco
The Ingenuity helicopter test flights on Mars in April 2021 marked the first time an aircraft has flown on another world. Students who have access to model helicopters and drones may wonder, how well could those fly on the Red Planet? The answer can be found in this journal [The Physics Teacher], using appropriate scaling of the surface gravity and atmospheric density to Martian values.
лошадь, диаграмма, Фейнман

Решение задач электростатики с помощью функции Грина

Подробно о подходе и задачи с ответами.

Using Green functions to solve potentials in electrostatics:
Y. F. Alam, A. Behne, W. S. Chisholm, J. Compton
In this paper, we summarize the technique of using Green functions to solve electrostatic problems. We start by deriving the electric potential in terms of a Green function and a charge distribution. We then provide a variety of example problems in spherical, Cartesian, and cylindrical coordinates. For a given coordinate system, we derive the corresponding Green function for some geometries, and then place an arbitrary charge distribution in the region; we then calculate the corresponding electric potential.
Comments: 15 pages, 3 figures