By using the projectile motion concepts, we can calculate, total time the ball is in the air = 3.06 seconds.
According to the projectile motion, we have
S = ut + (1/2) a [tex]t^{2}[/tex]
where s is the distance and u is the initial velocity and a is the acceleration and t is the time taken.
now putting the values we get
0 = 15* t + 0.5 * -9.8 * [tex]t^{2}[/tex]
15 x t = 4.9 [tex]t^{2}[/tex]
or we can write
t = 15/4.9
t = 3.06 s
Hence the total time taken during the ball going up and down is 3.06 second.
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