sliding home

Question
14u and 16u if a play is being made at the plate does the baserunner have to slide to avoid contact

Answer
There is no rule that ever requires a player to slide.  Also, the rules are written so that collisions are avoided.  
If a player comes into a base standing and there is hard contact with a defesive player in possession of the ball, this could easily be ruled malicious contact.  With that said sliding is always an attempt to avoid contact.