2 Part Algebra question please help

Question

NASA launches a rocket at t=0 seconds. Its height, in meters above sea-level, as a function of time is given by h(t)=−4.9t²+337t+143.

Assuming that the rocket will splash down into the ocean, at what time does splashdown occur?

1. The rocket splashes down after__________ seconds.

How high above sea-level does the rocket get at its peak?

1. The rocket peaks at ________ meters above sea-level.

Answer 1

For splash down - zero height

0 = −4.9t² + 337t + 143, can you slve for t and answer?

Highes point is at t = -337 / 2(-4.9), can you substitute t and answer?

Alternative is to complete the square and convet to vertex form.