Plugging in the given values gives us:
0 = -16t^2 + 80t + 145
This a quadratic equation with two roots. Solving it using using the quadratic formula or by factoring, or by any other solution, the roots are:
6.4531 and -1.4131
We are dealing with time, so we choose the positive root.
Therefore, the answer is 6.4531 seconds
