This seems a simple enough question, but Im not sure on how to go about solving it "What is the minimum positive initial velocity necessary for an object to be launched from ground level so that it reaches a height of 80 meters?" Multiple choice answers: a) 5m/s b) 9.8m/s c) 12.5m/s d) 40m/s e) 80m/s Well the problem doesnt give me a time, so im guessing it is asking that the object reaches at least 80m before it starts its fall back down. Can someone attempt to explain how I would get the answer? If I were simply guessing, I would go with either C or D, however, thats only guessing. Im sure gravity would someone used, but I dont know what to do with it.