Pronunciation of w at the end of a word - and what does ʊ mean?

On that symbol. It's here:

http://dictionary.cambridge.org/help/phonetics.html

that symbol is the short vowel "u" of "foot" and "book."

See also:

http://my-english-blackboard.blogspot.ca/2014/12/british-english-vowels.html

http://my-english-blackboard.blogspot.com.es/p/pronunciation-tips-u-and.html