1See, consider the metal ball:
let both of them be thrown with a velocity v (say)
Then, change in momentum of the metal ball = mv-0 = mv (its assumed to fall perpendicularly downwards, though it actually does not, but in reality, it falls literally downwards, with negligible velocity in the horizontal direction)
Consider rubber ball:
Initial momentum = mv.
Finally, it rebounds in the same direction, so it'll have some component of velocity in the reverse direction, say -v' (- sign indicates reverse direction)
So change in momentum = mv + mv' which is obviously greater than that of metal ball :)
anser is b)
:)
