Helppp hell hel hel Above On a disk is an iron cube of mass 200g, at a distance of 10cm from the axis of rotation of the disk, fig.3.95. The coefficient of friction of the rest of the cube with the disk is 0.4. Find: a) How many revolutions per minute does the disk make the moment the iron cube slides from the disk. b) The centripetal force acting on the cube before the moment of sliding from the disk.

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 -