1. The problem statement, all variables and given/known data A projectile launched straight up at 10 m/s will be in the air for: A) 1 s B) 1.4 s C) 2 s D) 5 s 2. Relevant equations Not sure. 3. The attempt at a solution I'm honestly not sure what to make of this problem. Since it's freefall, it sounds like we could assume the acceleration to be -10 m/s2. V0 would be equal to 10 m/s and V would equal 0 if it reaches a maximum height. If we need to find t and since we aren't given d, can we use the equation: v = v0+at?