Answer:
Step-by-step explanation:
initial velocity in horizontal direction = vx
Height = h
Let the time of light is t.
Use second equation of motion in vertical direction
h = ut + 1/2 at²
h = 0 + 0.5 gt²
![t=\sqrt{(2h)/(g)}](https://img.qammunity.org/2021/formulas/physics/college/op61j9riipefcg2rpwbi8l5sioka60sxm6.png)
So, to increase the time of flight, we have to increase the value of height.