Respuesta :
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 :
[tex]t = \frac{72\pm\sqrt{72^2-4\times 16\times 81}}{2\times 16}\\\\\implies t = \frac{72\pm 0}{32}\\\\\implies t = 2.25[/tex]
Hence, for 2.25 seconds the ball is 84 feet above the ground.
