A solid sphere of radius R contains a total charge Q distributed uniformly throughout its volume. Find the energy needed to asse
mble this charge by bringing infinitesimal charges from far away. This energy is called the "self-energy" of the charge distribution.
(Hint :After you have assembled a charge q in a sphere of radius r, how much energy would it take to add a spherical shell of thickness dr having charge dq? Then integrate to get the total energy.)
(Hint :After you have assembled a charge q in a sphere of radius r, how much energy would it take to add a spherical shell of thickness dr having charge dq? Then integrate to get the total energy.)
1 answer:
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Answer:
Explanation:
For an electromagnetic wave, the relationship between magnetic field amplitude and electric field amplitude is given by
where
E is the amplitude of the electric field
c is the speed of light
B is the amplitude of the magnetic field
For the electromagnetic wave in this problem, we have
E = 10 V/m is the amplitude of the electric field
So if we solve the formula for B, we find the amplitude of the magnetic field:
Answer:
La velocidad media es 5 , que equivale a 1.389
Explanation:
La velocidad es una magnitud física que expresa la relación entre el espacio recorrido por un objeto y el tiempo empleado para ello.
La velocidad media relaciona el cambio de la posición con el tiempo empleado en efectuar dicho cambio. Por lo que se calcula como la distancia recorrida por un objeto dividido por el tiempo transcurrido:
En este caso:
- distancia= 10 km= 10,000 m (siendo 1 km= 1,000 m)
- tiempo= 2 h= 7,200 s (siendo 1 h= 3,600 s)
Entonces, reemplazando en la definición de velocidad media:
Resolviendo se obtiene:
<u><em>La velocidad media es 5 </em></u><u><em>, que equivale a 1.389 </em></u>
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