initial speed of the ball by which it is kicked is 8 m/s
now the angle at which it is kicked is 20 degree
here we will have
[tex]v_y = v sin20[/tex]
[tex]v_y = 8 sin20 = 2.74 m/s[/tex]
now we will have
[tex]\Delta y = v_y t + \frac{1}{2}at^2[/tex]
so if the ball again land on the ground at same level then we have
[tex]\Delta y = 0[/tex]
[tex]0 = 2.74 t - \frac{1}{2}(9.8) t^2[/tex]
[tex]0 = 2.74 - 4.9 t[/tex]
[tex]t = 0.56 s[/tex]
so total time will be 0.56 s