1. The problem statement, all variables and given/known data If I throw a rock upwards with an initial velocity and throw a rock downwards, what is the speed of the rocks just before they hit the ground? 2. Relevant equations 3. The attempt at a solution\ They should hit the ground at the same speed and different times. I would use the conservation of mechanical energy, but someone I'm speaking to disagrees with me that they have same speed. How would you show this mathematically?