document.write( "Question 1077131: A model rocket is launched with an initial velocity of 164 ft/sec. Its height h, in feet, after t seconds is given by the formula h =16t^2-164t. After how many seconds will the rocket first reach a height of 348 ft?
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Algebra.Com's Answer #691675 by jorel1380(3719) $\"\"$ $\"About$

You can put this solution on YOUR website!
I think the proper equation for a projectile is h=-16t²+vt, where v is the initial velocity. Using that, we get:
\n" ); document.write( "348=-16t²+164t
\n" ); document.write( "So:
\n" ); document.write( "16t²-164t+348=0
\n" ); document.write( "4t²-41t+87=0
\n" ); document.write( "(4t-29)(t-3)=0
\n" ); document.write( "t=29/4 or 3
\n" ); document.write( "Using t=3 as our value, we get 3 seconds after launch as the time the rocket first reaches 348 ft. ☺☺☺☺ \n" ); document.write( "

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