Answer:
T = 0.225 s
Explanation:
The speed of a projectile at the highest point of its motion is the horizontal speed of the projectile. Considering the horizontal motion with negligible air resistance, we can use the following formula:
[tex]v_x = RT\\\\T = \frac{v_x}{R}[/tex]
where,
T = Total time of ball in air = ?
R = Horizontal distance covered = 40 m
[tex]v_x[/tex] = horizontal speed = 9 m/s
Therefore,
[tex]T = \frac{9\ m/s}{40\ m}[/tex]
T = 0.225 s