A child with a weight of 140 N swings on a playground swing attached to 2.20 m long chains. What is the gravitational potential energy (in J) of the child-earth system relative to the child's lowest position at the following times(a) when the ropes are horizontal (b) when the ropes make a 25.0° angle with the vertical (c) when the child is at the bottom of the circular arc

B, if it was a lower watt she could put it in for her normal time and not burn it

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 -