Okay, here's yet another headache waiting to happen: Galileo is atop the leaning tower of pisa,at a Height H. he throws down a cannonball with an initial velocity Vo, while his buddy down below throws another cannonball with initial velocity 2Vo at the bottom of the tower. a) in terms of Vo and H, at what time does the collision occur? *When the cannonballs collide, Galileo's cannonball has 7 times the velocity of his buddy's b) in terms of H only, at what height does the collision occur? I used kinematics for both of them and kinematics only. for part a, I got H/(3Vo), and for b I got H/4. Are these answers good and if not, should I be introducing like conservation of energy?... Thanks a bunch for anyone brave enough to step up to the challenge.