Awaterfall has a height of 700 foet. A pebble is thrown upward from the top of the falls with an initial velocity of 20 feet per second. The height of the pebble b in feet after t seconds is given by the equation - 161? + 20+ + 700. How long after the pebble is thrown wil it hit the ground?
The time it takes for the pebble to hit the ground is about
(Simplify your answer. Type an integer or decimal rounded to the nearest tenth as needed.)