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January 31, 2015

January 31, 2015

Posted by **Dixitz** on Thursday, August 22, 2013 at 10:39pm.

- Science -
**Steve**, Friday, August 23, 2013 at 4:44am5t - 4.9t^2 = 100 - 4.9t^2

t = 20

How can this be? The falling rock will hit the ground in 4.5 seconds. What it means is that the rock that was thrown upward will have fallen back to the ground (in 1.02 seconds) long before the falling rock arrives.

The only way this makes any sense is if the rock was thrown upward from the edge of a cliff, and both rocks could be in the air for 20 seconds.

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