The drawing shows an extreme skier at three locations on a ski run:
(a) a straight section,
(b) a circular section, and
(c) an airborne phase in which the skier is in free-fall. at the right of the drawing are four possible directions for the net force that acts on the skier. what is the direction of the net force at a, b, and c? assume that there is no friction or air resistance at any point along the ski run.

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 -

The answer is b hope this