Field Theory Answers

The Earth and the Moon may be considered to be uniform spheres that are isolated in space. The Earth has radius R and mean density ρ. The Moon, mass m, is in a circular orbit about the Earth with radius nR,

 The Moon makes one complete orbit of the Earth in time T.

Show that the mean density ρ of the Earth is given by the expression

ρ = 3πn^3/GT^2

Calculate the mass of the earth if the radius is approximately 6400km, if g=9.8m/s² and G=6.7×10–11Nm²kg–²

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A rectangular metal waveguide filled with a dielectric of relative permittivity εr = 4, has the inside dimensions 3 x 1.2 cm, the cut off frequency for the dominant mode is

Find the radiation resistance of an antenna of length λ/10 meter?

find electric field at center of square q=11.8 nC AND a=5.20cm

A point source q1=20nC is located at S(1,4).Determine some point near S, where the magnitude of the electric field E is equal to 30V/m

Is it possible to provide any kind of motion to a significant size of box if applied force is less then friction between surface and box