Nick is playing in his tree house 18 feet above the ground. He throws a baseball straight up in the air and then hits the ball with a bat to see how far it will go. The initial velocity of the baseball is 33 feet per second and the fall of the ball down to the ground can be modeled by the function ℎ()=−6^2+33+18. Determine at what time Nick should swing the bat to hit the ball.