1. A negative charge, -q, has a mass, m, and an initial
velocity, v, but is...
1. A negative charge, -q, has a mass, m, and an initial
velocity, v, but is infinitely far away from a fixed large positive
charge of +Q and radius R such that if the negative charge
continued at constant velocity it would miss the center of the
fixed charge by perpendicular amount b. But because of the Coulomb
attraction between the two charges the incoming negative charge is
deviated from its straight line course and attracted to the fixed
charge...
Consider permutations of the 26-character lowercase alphabet
Σ={a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}.
In how many of these permutations do
a,b,c...
Consider permutations of the 26-character lowercase alphabet
Σ={a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}.
In how many of these permutations do
a,b,c occur consecutively and in that
order?
In how many of these permutations does a appear before
b and b appear before c?
5. ABC-Free Permutations
Consider permutations of the 26-character lowercase alphabet
Σ={a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}.
In how many of these...
5. ABC-Free Permutations
Consider permutations of the 26-character lowercase alphabet
Σ={a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}.
In how many of these permutations do a,b,c occur consecutively
and in that order?
In how many of these permutations does a appear before b and b
appear before c?