A soccer ball is thrown upward from the top of a 204 foot high building at a speed of 112 feet per second. The soccer ball's height above ground can be modeled by the equation . When does the soccer ball hit the ground?

Respuesta :

Answer:

8.5 seconds to hit the ground

Step-by-step explanation:

A soccer ball is thrown upward from the top of a 204 foot high building at a speed of 112 feet per second.

[tex]h(t)=-16t^2+V_0t+h_0[/tex]

Vo is the speed 112 feet per second

h0 is the initial height = 204 foot

So the equation becomes

[tex]h(t)=-16t^2+112t+204[/tex]

When the soccer ball hit the ground then the height becomes 0

[tex]0=-16t^2+112t+204[/tex]

Apply quadratic formula

[tex]x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}[/tex]

[tex]t=\frac{-112+\sqrt{112^2-4 (-16) \cdot 204}}{2(-16)}[/tex]

[tex]t=\frac{-112+\sqrt{25600}}{-32}=-1.5[/tex]

[tex]\frac{-112-\sqrt{25600}}{-32}=8.5[/tex]

time cannot be negative

so it takes 8.5 seconds to hit the ground