Asubmarine is attempting to detect an aircraft carrier transiting the straits of malacca. the aircraft carrier has a source level of 90 db. the submarine's passive sonar has a directivity index of 20 db and a detection threshold of 15 db. biological noise in the straits is 54 db. the submarine's self noise is 50 db. given that tl = 10 log r, where r is the range in yards (we will show you where this comes from soon), at what range can the carrier just be detected?

An  atom  (ours, not carroll's) consists of a positively charged  nucleus, surrounded by one or more negatively charged particles called  electrons. the positive charges equal the negative charges, so the atom has no overall charge; it is electrically neutral. most of an atom's mass is in its nucleus; the mass of an electron is only 1/1836 the mass of the lightest nucleus, that of hydrogen. although the nucleus is heavy, it is quite small compared with the overall size of an atom. the radius of a typical atom is around 0.1 to 0.25 nanometres (nm), whereas the radius of a nucleus is about 10-6  nm.  *  if an atom were enlarged to the size of the earth, its nucleus would be only 200 feet in diameter and could easily rest inside a small football stadium.read more on -