1. The problem statement, all variables and given/known data An object is dropped from a height of 25m above the ground. What is the average velocity of the object as it falls to the ground? 2. Relevant equations d=vit+1/2at^2 3. The attempt at a solution d=-25 a=-9.8 vi=0 -25=-4.9t^2 t=2.3s vavg=displacement/time -25/2.3=-10.8m/s the answer in book says a=-11.1m/s i don't understand, please help?