DeSean throws a ball up with an initial vertical velocity of 30 ft/s from a platform that is at ground level. How long will the ball be in the air?

Answer: Time, t = 1.875 secondsStep-by-step explanation:It is given that,Initial velocity of the ball, u = 30 ft/sDeSean throws a ball from a platform that is at ground level. The equation of motion when an object is thrown vertically upward is given by the following equation as :[tex]h(t)=-16t^2+vt+h[/tex]Here, h = 0 since, the ball is thrown up at the ground level. We have to determine the time when the ball be in air. The quadratic equation becomes :[tex]-16t^2+30t+0=0[/tex]t = 1.875 seconds  So, the ball be in air for 1.875 seconds. Hence, this is the required solution.