Walking across a bridge, a tourist throws a penny into the water below. The penny's height above the water in meters, p(x), depends on the time in seconds after throwing, x, and can be modeled with the function p(x) = -16x2+ 7x + 15. Approximately how many seconds after being thrown will the penny hit the water? 0.2 seconds 15.8 seconds 1.2 seconds 15 seconds​