Answer:
The time at maximum height is 2.49 s.
Explanation:
The time (t) at the maximum height can be found using the following equation:
[tex] v_{f} = v_{0} - gt [/tex]
Where:
[tex]v_{f}[/tex]: is the final velocity = 0 (at the maximum height)
[tex]v_{0}[/tex]: is the initial velocity = 80 ft/s
g: is the gravity = 9.81 m/s²
Hence, the time is:
[tex]t = \frac{v_{0}}{g} = \frac{80 \frac{ft}{s}*\frac{1 m}{3.281 ft}}{9.81 m/s^{2}} = 2.49 s[/tex]
Therefore, the time at maximum height is 2.49 s.
I hope it helps you!