A small sphere freely falling from a certain height after striking the floor rebounds and rises to same height. When is it possible ?

A small sphere freely falling from a certain height after striking the

1.	A small sphere freely falling from a certain height after striking the floor rebounds and rises to same height. When is it possible ?
Answer» SOLUTION : A.Here `E = sqrt (( H _(2))/( h _(1))) =1,`This is POSSIBLE when the collision is CLASTIC.