let s(t)= -16t^2 + 50 represent the distance in ft. from the ground of an object t seconds after initial velocity of the object? initial means t=0

1. what is the initial velocity of the object?
2. what is the velocity of the object 1 sec after it was released?
3. when does the object hit the ground?
4. what is the object's velocity as it his the ground?