Awater has a height of 700 feet . A pebble is thrown upward from the top of the falls with an initial velocity of 20 per second. The height of the pebble hin foet ufort seconds is given by the equations h= -16t^2+20t+700. How long after The pebble is thrown with the ground?
The time takes for the pebble to hit the ground is about ___
(Simply your answer. Type airger or decimal rounded to the nearest ton as needed)