high school grade 3
posted by farnoosh .
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?

Well we could assume that the force up from the slush on the ball is constant and that the kinetic energy of the ball goes into work, force times depth
F d = (1/2) m v^2 = m g h
if d is twice then h is twice