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Tabbiejack

If an object is dropped from a height of 144 feet, the function h(t)= -16t^2+144 gives the height of the object after t seconds. When will the object hit the ground? A. 9 s B. 6 s C. 1.5 s D. 3 s

  • 11 months ago
  • 11 months ago

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  1. whpalmer4
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    well, solve the equation for h = 0...what positive value of t makes it so?

    • 11 months ago
  2. whpalmer4
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    at t = 0, h(0) = -16(0)^2 + 144 = 144 feet, which is the height from which it is being dropped. at some later t, h(t) = 0, and that's when it hits the ground.

    • 11 months ago
  3. whpalmer4
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    \[h(t) = 0 = -16t^2+144\]\[16t^2=144\]\[t=\]

    • 11 months ago
  4. Tabbiejack
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    so it 9

    • 11 months ago
  5. whpalmer4
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    does 16*9*9 = 144?

    • 11 months ago
  6. whpalmer4
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    always, always check your answers in the original formula to make sure they correctly answer the question.

    • 11 months ago
  7. Tabbiejack
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    no

    • 11 months ago
  8. Tabbiejack
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    its 3

    • 11 months ago
  9. passive13
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    it is 3 gj

    • 11 months ago
  10. whpalmer4
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    16(3)(3) = 144, so that is a reasonable answer. Note that t = -3 also satisfies the equation, but does not satisfy the conditions described in the problem, so it is not a correct solution here.

    • 11 months ago
  11. Tabbiejack
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    ok

    • 11 months ago
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