A stone is thrown from the top of a building by an initial velocity of 21.7 m/s straight upward, at an initial height of 54.9 m above the ground. The stone just misses the edge of the roof on its way down, as shown in the figure.
1. Decide the maximum height.
2. Decide the time needed for the stone to reach its maximum height.
3. Decide the velocity and position of the stone at t = 6.39 s.
4. Decide the time needed for the stone to reach the ground.
5. Determine the time needed for the stone to return to the height from which it was thrown, and the velocity of the stone at that instant. (Time and velocity)