if drop down an stone -that it is like a ball- into the slush and if it was soft enough stone come into the slush in some distance, if throw it away from a certain height to comes into slush and if we want stone to come into slush 2 times more than before from what hight should we throw it away?

Answer 1

Thought I did this yesterday
Ke at hit = Pe at top = m g h
m g h = F d
assume F from slush is constant maybe
then doubling d, the depth happens when doubling h