WOLFRAM|DEMONSTRATIONS PROJECT

Energy Density of a Particle Moving at Uniform Speed

​
contourplot
electric energy density
magnetic energy density
E
z
B
z
S
z
vectorfield
xy component of electric field
xy component of magnetic field
xy component of Poynting vector
z position
10
velocity
100000000
time
0
The four components of the potential
A
μ
ϕ,
v
2
c
ϕ,0,0
of a point charge, whose position at the time
t
is
(vt,0,0)
, at the observation points
-∞<t,x,y,z<∞
are used to compute various electric and magnetic properties. The time component is the scalar potential
ϕ
and the three space components are the vector potential (
v
2
c
ϕ
, 0, 0). The system is rotationally symmetric around the
x
axis. The scalar potential for cylindrical coordinates,
ϕ(t,ρ,φ,x,v)
, is independent of
φ
. The observation plane is parametrized by
-h<x,y<+h
with
h
= 50 meters with an arbitrary
z
value. The charge enters the observation plane at time
-h/v
with
1×
8
10
m/s<v<2.99×
8
10
m/s
. At
t=0
the charge passes the origin with positive speed
v
. The charge leaves the observation plane at time
h/v
. The five independent variables are
t,x,y,z,v
. The electric and magnetic field vectors, the Poynting vector, and the energy density are displayed on the observation plane. SI (MSKA) units are used.