Answer:
1.8 sec
Explanation:
Consider the motion of the ball in downward direction as positive
v₀ = initial speed of the metal ball = 8.55 m/s
a = acceleration of the ball = 9.8 m/s²
y = vertical displacement of the ball = height of the structure = 30.6 m
t = time taken by the ball to hit the ground
Using the equation
y = v₀ t + (0.5) a t²
30.6 = (8.55) t + (0.5) (9.8) t²
t = 1.8 sec
