SOLUTION: A ball is dropped from a cliff that is 464 feet high. The distance S (in feet) that it falls in t seconds is given by the formula S = 464 - 16t^2. How many seconds (to tenths) wi

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Question 622431: A ball is dropped from a cliff that is 464 feet high. The distance S (in feet) that it falls in t seconds is given by the formula S = 464 - 16t^2. How many seconds (to tenths) will it take for the ball to hit the ground?
Answers I can choose from:
21.2 sec
5.4 sec
21.5 sec
13,456 sec

Found 2 solutions by nerdybill, Alan3354:
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
A ball is dropped from a cliff that is 464 feet high. The distance S (in feet) that it falls in t seconds is given by the formula S = 464 - 16t^2. How many seconds (to tenths) will it take for the ball to hit the ground?
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Set s to zero and solve for t:
S = 464 - 16t^2
0 = 464 - 16t^2
-464 = -16t^2
464 = 16t^2
29 = t^2
5.4 seconds = t

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
A ball is dropped from a cliff that is 464 feet high. The distance S (in feet) that it falls in t seconds is given by the formula S = 464 - 16t^2. How many seconds (to tenths) will it take for the ball to hit the ground?
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The distance S (in feet) that it falls in t seconds is given by the formula S = 464 - 16t^2.
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That's not true.
s in ft = 16t^2 is the distance it falls.
Its height above the ground = 464 -16t^2
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At impact, h = 0
464 - 16t^2 = 0
t^2 = 29
t =~ 5.4 seconds