Question 30280
THe formula is given by :
*[tex h=vt-16t^2]
WHere v is the velocity:
*[tex h=144t-16t^2]
Differentate and multiply the result by 2
*[tex \frac{d(144t-16t^2)}{dx}=144-32t]

<pre>32t=144
t=4.5
2(4.5)=9


Or you can factor it:
*[tex h=144t-16t^2]
*[tex h=16t(9-t)]
you get:
t=0 or t=9

<b>
<font color = red>Hence, the time for the flare to return to the sea is 9 second.</font>
Paul.