Question 598560: in a cartoon, a malfunctioning cannon fires a hungry coyote towards the bottom of a cliff with an initial rate of 100 feet per second. if the cliff is 1250 feet tall, how long will it take the coyote to reach the desert floor? ( To account for gravity, use the formula d=rt + 16t^2 , where d = distance, r= inital rate,and t=time).
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website! in a cartoon, a malfunctioning cannon fires a hungry coyote towards the bottom of a cliff with an initial rate of 100 feet per second. if the cliff is 1250 feet tall, how long will it take the coyote to reach the desert floor? ( To account for gravity, use the formula d=rt + 16t^2 , where d = distance, r= inital rate,and t=time).
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h(t) = -16t^2 + rt + h
h = initial height = 1250 ft
r = -100 ft/sec, negative going down
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h(t) = -16t^2 - 100t + 1250
Find t when h(t) = 0
-16t^2 - 100t + 1250 = 0
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| Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc) |
Quadratic equation  (in our case  ) has the following solutons:
For these solutions to exist, the discriminant  should not be a negative number.
First, we need to compute the discriminant :  .
Discriminant d=90000 is greater than zero. That means that there are two solutions:  .
Quadratic expression  can be factored:
Again, the answer is: -12.5, 6.25.
Here's your graph:
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Ignore the negative solution.
t = 6.25 seconds
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