Find the center of mass of a rectangular material of length a and width b made up of a material of non-uniform density the density is such that when the rectangle is placed in the xy-plane, the density is given by ρ(x, y) = ρ0xy.

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?