document.write( "Question 1120524: An object is propelled vertically upward with an initial velocity of 20 m/s. The distance s (in meters) of the object from the ground after t seconds is given by $\"+s%28t%29+=+-4.9t%5E2+%2B+20t+\"$ . When will the object be 15 meters above the ground? \n" ); document.write( "

Algebra.Com's Answer #736194 by ikleyn(52754) $\"\"$ $\"About$

You can put this solution on YOUR website!
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\n" ); document.write( "\n" ); document.write( " $\"+s%28t%29\"$ = $\"-4.9t%5E2+%2B+20t+\"$ . When will the object be 15 meters above the ground?
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\n" ); document.write( "\n" ); document.write( "I am here to edit the Alan's solution, which is not exactly correct.\r
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document.write( "when s(t) = 15.\r\n" );
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document.write( " = \r\n" );
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document.write( "Solve for t.\r\n" );
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document.write( "You get 2 times, ascending & descending.\r\n" );
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document.write( "Plot y =  (red)  and  y = 15 (green)\r\n" );
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