a wave propagates in free space and its electric field is j75z (a) show that e satisfies the source-free wave equation. this prob lem asks you to show satisfaction of the wave equation, not the helmholtz equation. (b) what are the wave's phase velocity and frequency?

Estimate the kinetic energy of mars with respect to the sun as the sum of two terms, that due to its daily rotation about its axis, and that due to its yearly revolution about the sun. (assume mars is a uniform sphere with mass = 6.4×10 to the power of 23 kg, radius = 3.4×10 to the power of 6 m, rotation period = 24.7 hours, orbital period = 686 days and is 2.3×10 to the power of 8 km from the sun.)