We have to calculate the number of seconds for the flare to return to the sea.
We have an initial vertical speed of 448 ft/s.
The only force acting on the flare is gravity.
Then, we can model the heigth in function of time using the equation:
[tex]h(t)=h_0+v_yt-\frac{g}{2}t^2[/tex]
where h0 = 0 ft, vy = 448 ft/s and g = 32 ft/s².
Then, we can replace and calculate t for h(t) = 0, that is the time it took the flare to come back to the initial height (that is 0 ft):
[tex]\begin{gathered} h(t)=0 \\ h_0+v_yt-\frac{g}{2}t^2=0 \\ 0+448t-\frac{32}{2}t^2=0 \\ 448t=16t^2 \\ 448=16t \\ t=\frac{448}{16} \\ t=28 \end{gathered}[/tex]
Answer: it will take 28 seconds for the flare to return to the sea [Third option].
