Answer:
The rocket would be in the air for 8.125 seconds after launch.
Explanation:
Given that the height of the rocket, h = 260t - 16
.
To determine how long the rocket would be in the air, differentiate h totally with respect to t.
So that, total derivative of h is given as;
=

0 = 260 - 16 x 2t
= 260 - 32t
0 = 260 - 32t
32t = 260
t =

= 8.125
t= 8.125 seconds
The rocket would be in the air for 8.125 seconds after launch.