Write an expression for the potential energy UD of a particle when it is at a distance D from the force center, in terms of B and D, where B is the constant of proportionality. Assume the potential energy to be zero when the particle is at infinity.

An electromagnetic wave with frequency 65.0 hz travels in aninsulating magnetic material that has dielectric constant 3.64 andrelative permeability 5.18 at this frequency. the electric fieldhas amplitude 7.20 \times 10^{ - 3} {\rm v}/{\rm m}. a. what is the speed of propagation of the wave? b.what is the wavelength of the wave? c.what is the amplitude of the magnetic field? d.what is the intensity of the wave?