Consider a temn mode in a rectangular waveguide. find the time-averaged poynting vector(s) and energy density 〈u). integrate over the cross-section of the waveguide to obtain the energy per unit time and the energy per unit length carried by the wave. calculate their ratio. confirm that the energy in the mode travels at the group velocity vg - do/dk.

increasing transnational kinetic energy. because the transnational kinetic energy formula consists of only two variables, mass and velocity, increasing one of those properties is the only way to increase an object's transnational kinetic energy. increases to mass and velocity, however, do not have the same impact.

wire in brush may conduct electricity from cell to drill and vice versa electrc shock possible

myth. it was once thought that animals, including cats and dogs, could only see in black and white. however, scientists have proven this to be a myth. in all animals, including humans, the perception of colour is determined by the presence of cells in the eye called cone photoreceptors.