SOLUTION: If one throws a ball down from a high cliff, the distance it travels can be modeled by the equation: LaTeX: d = -9.8t^2-15t+100 d = − 9.8 t 2 − 15 t + 100 where t is the time

Question 1142926: If one throws a ball down from a high cliff, the distance it travels can be modeled by the equation: LaTeX: d = -9.8t^2-15t+100 d = − 9.8 t 2 − 15 t + 100 where t is the time in seconds and d is the distance in meters.
1. At what time will the ball hit the ground?
2. You will get two answers because this is a quadratic equation. Do both make sense? (Explain in detail Why or Why not).
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!

The ball is thrown downward at

so, the cliff is 100 m high
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What is when

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can't use this result since the answer is negative

sec
The ball hits the ground in 2.52 sec ( rounded off )
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Note that the problem is not stated correctly.
is not the distance that the ball travels,
but it is the distance above ground from sec
to sec
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Check:
Does ?

The error is due to rounding off
OK
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