When I was a student, I remember they taught me that the method of images to solve the problem of finding the electrostatic potential outside a grounded conducting sphere in the presence of an external point charge is a kind of miracle. But in physics, there are not miracles. Here are the facts why the method works

There are several problems on ballistic that illustrate in a straightforward manner the application of Newton’s equations to parabolic motion. Think for example that a projectile is launched in front of a fence of height located at a distance from the place of firing.

Here is an example of the application of Newton’s second law of motion to a ballistic problem. The problem we want to consider is calculating the critical angle of firing a projectile from the ground toward a high place (of height ), located at a distance in front of the place of firing.

Ballistic motion is one of the more elementary problems where the application of Newton’s second law is straightforward. The problem to be considered in the present article is the calculation of the critical angle of firing a projectile of mass with initial velocity , that leads to a maximum horizontal reach .

A system consisting of a rope falling down a table is considered nontrivial by many students due to the differential equation to be solved to obtain the dependence on time of the position and velocity of the rope.

Here I will take a top-to-bottom approach to introduce the theory of general relativity. Thus, I present from start the field equations. The field equations are extremely compact in the usual form that they are presented.

In this short article, I’ll give a geometric motivation for the definition of the inner product of vectors ( also called scalar product). The objects that we will be considering are arrows in the three-dimensional space and they will be represented by Latin letters.

The Maxwell equations are a set of four partial differential equations that describe the spatial and temporal behavior of electric and magnetic fields. The sources of time-independent electric and magnetic fields are the time-independent electric charge density and the steady current density respectively.

Acceleration in special relativity is not parallel to the applied force. This is in contrast to the case of classical mechanics where Newton’s second law implies that force and acceleration are parallel by definition. In the present article, this result is derived in a simple form.

In the present article, we consider the collision of two particles , and , with at rest in the lab frame of reference before the collision. As a result of the collision one or more particles , are produced. The produced particles can be, in principle, different from the colliding ones.