help on this problem?!?

A diver is standing on a platform 24 ft. above the pool. He jumps from the platform with an initial upward velocity of 8ft/s. Use the formula h(t) = -16t^2 + vt + s, where h is his height above the water, t is the time, and v is his starting upward velocity, and s is his starting height. How long will it take for him to hit the water?

L. E. Gant2019-02-27T21:14:39Z

0 = -16t^2 + 8t + 24
==> 0 = 2t^2 -t -3
==> 0 = (2t - 3)(t + 1)
solve for t
==> t = -1 or t = 3/2 seconds.