The height above ground level in meters of missile launched vertically is given by. h(t)= -16tcupe plus 100t.

Question

At what time is the missile 72m above ground level? (t is time in second)

Answer 1

given your equation, just solve
-16t^3 + 100t = 72
However, the trajectory of a missile is a parabola, so you want

-16t^2 + 100t = 72
or, dividing by -4,
4t^2 - 25t + 18 = 0
just solve in the usual way.
and the height is in feet, not meters. in metric units, g = 9.81, not 32.

Answer 2

Equation