SOLUTION: A rock is thrown upward from the top of a 250-foot cliff with a velocity of 14 feet per second. The height, h, in feet of the object after t seconds is h = –16t2 + 14t + 250. Appro

Algebra ->  Equations -> SOLUTION: A rock is thrown upward from the top of a 250-foot cliff with a velocity of 14 feet per second. The height, h, in feet of the object after t seconds is h = –16t2 + 14t + 250. Appro      Log On


   



Question 292003: A rock is thrown upward from the top of a 250-foot cliff with a velocity of 14 feet per second. The height, h, in feet of the object after t seconds is h = –16t2 + 14t + 250. Approximately how long after the object is thrown will it strike the ground below?

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
A rock is thrown upward from the top of a 250-foot cliff with a velocity of 14 feet per second.
The height, h, in feet of the object after t seconds is h = –16t^2 + 14t + 250.
Approximately how long after the object is thrown will it strike the ground below?
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Plot this equation:
+graph%28+300%2C+200%2C+-2%2C+6%2C+-100%2C+300%2C+-16x%5E2%2B14x%2B250%29+
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Looks like it will strike the ground in 4.4 sec
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If you want the exact time, use the quadratic formula to find the positive solution
a=-16; b=14; c=250
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Response to student comment:
I did use a TI83 to graph the equation, y = -16x^2+14x+250 with a scale:
Window: -2,6,1 and -100,300,20 to get the graph you see
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But you can graph it on graph paper, by making a table and plotting the x,y points. If you want me to help you do that, my email ankor@att.net
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What are you confused about?
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