The answer is attract. Hope it helps! :)
Answer:
7.45 s.
Explanation:
Given:
h = 68.1 m
vi = 0 m/s
vf = 42.4 m/s
g = 9.81 m/s^2
Using,
h = vi*t +1/2*(a*t^2)
68.1 = 1/2 * (9.81*t^2)
t = sqrt((68.1*2)/9.81)
= 3.726 s.
Total time of flight = 2*t
= 2 * 3.726
= 7.45 s.
The sound gets louder as it gets closer and when it passes is gets softer
Pressure
= Force/Area
Area = π(d^2)/4
= π(0.4^2)/4
=0.126 m2
Pressure
= 50/0.126
= 396.825 Pa