A stone is dropped from a height of 32.4m above the ground. Calculate the velocity of this object when it reaches the ground. the step by step ans key shows that acceleration is -9.81m/s^2. y is it neg? is it bc the object is going downwards(neg direction)? if that's the case, then y in this question pos acceleration is used?: A large steel ball is dropped from a height of 7.00m above the floor. What is the velocity that the object will strike the floor?