Answer:
For 2.25 seconds the ball is 84 feet above the ground.
Step-by-step explanation:
Initial height when the ball is kicked = 3 feet
Initial velocity of the soccer ball = 72 feet per second
The height(h) of the vertical thrown object is modeled by the formula :
h(t) = -16t² + vt + s , where t is the time, v is initial velocity and s is initial height
Now, h(t) is given to be 84 feet and we need to find the time taken by the ball to reach 84 feet above the ground :
84 = -16t² + 72t + 3
⇒ 16t² - 72t + 81 = 0
Finding roots of this equation :

Hence, for 2.25 seconds the ball is 84 feet above the ground.