Part one:
an amusement park ride consists of a rotating
circular platform 8.78 m in diameter from
which 10 kg seats are suspended at the end
of 3.54 m massless chains. when the system
rotates, the chains make an angle of 40.7◦ with the vertical.
the acceleration of gravity is 9.8 m/s^2.
what is the speed of each seat?
answer in units of m/s.

part two
if a child of mass 49.1 kg sits in a seat, what is
the tension in the chain (for the same angle)?
answer in units of n.

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 -

Iagree c would be the answer