The height of an object after it is released can be modeled by the function f (x) = negative 16 t squared + v t + s, where t is the number of seconds after the object is released, v is the upward speed in feet per second at release, and s is the starting height in feet. If a quarterback throws a ball from his hand 6 feet in the air at an upward speed of 25 feet per second, how much time does his teammate have to catch the ball?