A cherry falls from a tree branch that is 9 feet above the ground.a.what is the height of the cherry after 0.2 seconds? ______________b.after how many seconds does the cherry hit the ground?
Question
Answer:
The cinematic equation is:h (t) = (1/2) * a * t ^ 2 + vo * t + h0
Where,
a: acceleration
vo: initial speed
h0: initial height
Substituting values:
h (t) = (1/2) * (- 32) * t ^ 2 + (0) * t + 9
h (t) = - 16t ^ 2 + 9
For t = 0.2 we have:
h (0.2) = - 16 * (0.2) ^ 2 + 9
h (0.2) = 8.36 feet
To touch the ground we have:
-16t ^ 2 + 9 = 0
16t ^ 2 = 9
t = root (9/16)
t = 0.75 s
Answer:
The height of the cherry after 0.2 seconds is:
h (0.2) = 8.36 feet
the cherry hits the ground at:
t = 0.75 s
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10 months ago
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