Project Seafarer was an ambitious program to construct an enormous antenna, buried underground on a site about 10 000 km2 in area. Its purpose was to transmit signals to submarines while they were deeply submerged. If the effective wavelength were 1.0 x 104 Earth radii, what would be the

(a) Frequency and

(b) Period of the radiations emitted? Ordinarily, electromagnetic radiations do not penetrate very far into conductors such as seawater.