Yes, Bernie Sanders supports causes related to the platform that Hillary Clinton also supports. These causes such as education, the environment and regulation of the banking industy are important to young voters that support Senator Sanders. With an choice between Clinton and Trump, these voters will continue to align with Sanders and support Clinton.
Although many more vocal Sanders followers have adopted a "Bernie-or-bust" position, the less vocal portion of his followers may very well be in support of Clinton due to Sanders' repeated endorsements. Indeed, the majority of voters that would prefer Sanders over clinton could be reasonable; however, their opinions may be underreported.
Yes, Bernie Sanders' endorsement for Hillary Clinton is likely to persuade young voters to vote the democratic ticket in the upcoming election. Voters who advocated for Sanders trust him and believe in his ability to make change. His endorsement carries weight with young voters because he is still keeping to his values but showing that he supports the democratic party.
Bernie Sanders is responsible for the immense liberal political movement that asks for greater economic equality, among other key issues. He didn't win the nomination so now he is stumping for Hillary Clinton. His support of Clinton isn't going to be effective, though, especially in terms of the youth vote. Young voters are disillusioned, and aren't convinced that Clinton will help them.