It has a military aircraft and a submarine communication

It has a military aircraft and a submarine communication system at 100MHz. Assuming that the signal sent from the plane comes to the sea surface in a normal direction and has a power density of S = 20W / m2, find the expressions alan and H in the sea water. B) The receiver antenna of the submarine needs a power density of at least 14W / cm² of the signal level in the seawater to communicate. Calculate the depth of the submarine to the sea surface so that it can communicate with the aircraft. For sea water, take o = 4.5 S / m, & = 80, ur = 1. Gap impedance no = 376.734322