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Suppose a soccer ball is kicked from the ground at an angle 20.0º above the horizontal at 8.00 m/s. The y-velocity is determined to be 2.74 m/s. How long will the ball be in the air? Assume the ball lands at the same height at which it was kicked.

Respuesta :

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

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