Compute the energy density of the electric field.

+3 votes

On a clear day at a certain location, a 112-V/m vertical electric field exists near the Earth's surface. At the same place, the Earth's magnetic field has a magnitude of 4.400 image 10-5 T.


(a) Compute the energy density of the electric field.
 nJ/m3

(b) Compute the energy density of the magnetic field.
 µJ/m3
asked Mar 6, 2012 in Physics by apush ~Expert~ (552 points)
    

1 Answer

+1 vote

Part A:

The energy density of the electric field is given by:

energy density of the electric field  = (1/2) * permitivity of free space* E^2  (*where E=electric field)

permitivity of free space = 8.8542 * 10^-12 C^2/N*m^2

 

Part B:

the energy density of the magnetic field is given by:

energy density of the magnetic field = (1/2) * B^2 / permeability of free space (*where B=magnetic field)

permeability of free space = (4*pi) * 10^-7   T*m/A

 

answered Mar 14, 2012 by kirby ~Expert~ (3,020 points)



...