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Becky found a tennis ball outside a tennis court. She picked up the ball and threw it over the fence into
the court. The path of the tennis ball can be represented by h = -16t2 + 80t, where h represents the
height of the tennis ball in feet and t represents the time in seconds.
31. Find the maximum height of the tennis ball.
32. How long will it take for the tennis ball to hit the ground?

Becky found a tennis ball outside a tennis court She picked up the ball and threw it over the fence into the court The path of the tennis ball can be represente class=

Respuesta :

Answer:

31). Maximum height = 100 feet

32). Time to hit the ground = 5 seconds

Step-by-step explanation:

31). Equation modeling the height 'h' of the ball is,

     h = -16t² + 80t

     For the maximum height of the ball,

     Find the derivative of 'h' with respect to time 't' and equate it to zero.

     [tex]\frac{dh}{dt}=\frac{d}{dt}(-16t^2+80t)[/tex]

          [tex]=-32t+80[/tex]

     [tex]\frac{dh}{dt}=0[/tex]

     [tex]-32t+80=0[/tex]

     [tex]t=\frac{80}{32}[/tex]

     [tex]t=2.5[/tex] seconds

     That means after 2.5 seconds ball will reach the maximum height.

     By substituting [tex]t=2.5[/tex] in the equation,

     [tex]h=-16(2.5)^2+80(2.5)[/tex]

     [tex]h=100[/tex] feet

     Therefore, maximum height achieved by the ball is 100 feet.

32). If the ball follows the parabolic path,

      Time taken by the ball to reach the maximum height = Time taken by  the ball to come back to the ground from the maximum height.

      Time taken by the ball to hit the ground = 2(2.5) = 5 seconds