document.write( "Question 668717: How do I solve this?\r
\n" ); document.write( "\n" ); document.write( "A projectile is thrown upward so that its distance above the ground after t seconds is
\n" ); document.write( "h=-13t^2+520t. After how many seconds does it reach its maximum height?
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Algebra.Com's Answer #716006 by ikleyn(52806) $\"\"$ $\"About$

You can put this solution on YOUR website!
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document.write( "Double check the number \"13\" in your post.\r\n" );
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document.write( "Usually (as a rule) this number for the Earth conditions is EITHER 16 (when the height is measured in feet)  \r\n" );
document.write( "OR  5  (when the height is measured in meters).\r\n" );
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document.write( "It is for the first time I see the number \"13\" in such problems.\r\n" );
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document.write( "But if they are talking about a projectile launched at the other planet surface . . . \r\n" );
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document.write( "then everything may happen . . . \r\n" );
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