A group of students are provided with three objects all of the same mass and radius. The objects include a solid cylinder, a thin hoop (or cylindrical shell), and a solid sphere. The students are asked to predict which will get to the bottom of a ramp first if all three are released together from the same distance up the ramp. Which prediction is correct if the objects are listed in order from fastest to slowest

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 -