Hor and Hulk are fighting eachother, back and forth in a straight line in the master's colosseum. Hulk punches thor into a wall 30 meters away from the start. Thor then hit's hulk with a hammer, hurling Hulk 45 meters back from the wall. This all happens in the course of 3 seconds. What is the speed of their fight across the arena? a. 25 m/s
b. 10 m/s forward from Hulk and Thor's starting point.
c. 5 m/s backwards from hulk's starting point
d. 5 m/s

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 -