Question 1077131
I think the proper equation for a projectile is h=-16tē+vt, where v is the initial velocity. Using that, we get:
348=-16tē+164t
So:
16tē-164t+348=0
4tē-41t+87=0
(4t-29)(t-3)=0
t=29/4 or 3
Using t=3 as our value, we get 3 seconds after launch as the time the rocket first reaches 348 ft. ☺☺☺☺