these are two words i always get confused when using in a sentence. it gets frustrating.

Why is it "in" a video but "on" a tv and "on" a cd.
"in" a newspaper or "in" a book but then "on" facebook, etc
"in" a group but "on" a team.
"in" a car but "on" a bus.
can anybody shed light on this matter, yet another example "on" a matter but "in" a situation.

a little extra question on the side, i've heard somebody say this "in" an interview put an image "to" a word. why not "on"? the interview was about learning a new language according to a polyglot.

many thanks!