A ball is thrown vertically upward from the top of a buildin
A ball is thrown vertically upward from the top of a building 128 feet tall with an initial velocity of 112 feet persecond. the distance s (in feet) of the ball from the ground after t seconds is s =128 +112t-16t2. after how many seconds will the ball pass the top of the buildings.
Solution
s = 128+112t-16t^2
 128 = 128+112t-16t^2
 0 = 112t-16t^2
 0 = t(112-16t)
 
 t = 0
 or
 16t = 112
 t = 112/16
 t = 7
 
 Answer:
 Obviously the ball is at building height at 0 seconds,
 but the answer to the question is that it will pass
 that same height after 7 seconds.

