If we look at the first half of the trip as the ball travels upwards, it starts at a velocity of 25 m/s, and at the peak of its trajectory, it will have a velocity of 0 m/s. We can use the formula v_f = v_i + at to calculate time. Plugging in these values and the acceleration due to gravity yields:

v_f = v_i + at 0 m/s = 25 m/s + (-10 m/s²) t -25 = -10t 2.5 seconds = t

However, 2.5 seconds is only the time needed to reach the top of the trajectory. We must multiply this number by 2 to account for the time it takes the ball to come back down, yielding 5 seconds.

Please explain where the -10 m/s squared for acceleration of the ball came from