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Home > GC > Chapter 12 > Lesson 12.2.4 > Problem 12-87

12-87.

Perry threw a tennis ball up into the air from the edge of a cliff. The height of the ball was , where y represents the height in feet of the ball above ground at the bottom of the cliff, and represents the time in seconds after the ball is thrown.

  1. How high was the ball when it was thrown? How do you know?

    Substitute in for .

  2. What was the height of the ball seconds after it was thrown? What was its height a second after it was thrown? Show all work.

    Use the same method you used to solve part (a).




    ft




    8 ft

  3. When did the ball hit the ground? Write and solve an equation that represents this situation.

    If the ball hits the ground, what is its height above the ground?




    seconds