the answer is NE^0.5 but my answer is E^0.5N
the # of state is Ω=( one particle phase-space volume)^N
one particle phase-space volume=integration of dq*integration of dp
from space part dq I get V and dp is converted into Energy E variable via E=p^2/2m
for the case, r>>r' the higher-order term like 1/r^2 and above that is negligible.
so V(r)=cons.*1/r*P0(cos a)
but for the case r'>>r will it be V(r)=cons.*1/r'[ summation Pn(cos a')t'^n] where t'=r/r'
now if we neglect higher-order term of r/r' then V(r)=cons.*1/r'*P0(cos a') which is...