document.write( "Question 122161: A rocket is launched into the air. The height in feet, of the rocket, above the ground is given by h(t)=-4.9t(squared) + 192t, where t represents the time in seconds after the launch. (Hint:draw a picture)
\n" ); document.write( "#1. How long is the rocket in the air before it reaches the ground?
\n" ); document.write( "#2. How long does it take the rocket to reach its highest point?
\n" ); document.write( "#3. How high is the rocket at its highest point? I know that to find this answer I use the formula for the line of symmetry, and the vertex is the highest point..I think that it is 19.6 feet if I did it right.\r
\n" ); document.write( "\n" ); document.write( "The other questions I do not know how to do.\r
\n" ); document.write( "\n" ); document.write( "Thank you!
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Algebra.Com's Answer #89679 by josmiceli(19441)\"\" \"About 
You can put this solution on YOUR website!
I can plot this
\n" ); document.write( "\"+graph%28+600%2C+600%2C+-5%2C+50%2C+-50%2C+2000%2C+%28-4.9%29%2Ax%5E2+%2B+192x%29+\"
\n" ); document.write( "\"h%28t%29+=+-4.9t%5E2+%2B+192t\"
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\n" ); document.write( "(1) I need to find the change in \"t\" when th3e
\n" ); document.write( "rocket goes from (t,h) = (0,0) to (t,0) where \"t\" is the
\n" ); document.write( "time to fall back to earth
\n" ); document.write( "\"h%28t%29+=+-4.9t%5E2+%2B+192t\"
\n" ); document.write( "\"0+=+-4.9t%5E2+%2B+192t\"
\n" ); document.write( "\"t%2A%28-4.9%2At+%2B+192%29+=+0\"
\n" ); document.write( "One solution is \"t+=+0\" This is the point (0,0)
\n" ); document.write( "The other solution is \"-4.9%2At+%2B+192+=+0\"
\n" ); document.write( "\"4.9%2At+=+192\"
\n" ); document.write( "\"t+=+39.184\" sec (this agrees closely with graph)
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\n" ); document.write( "(2) The highest point is where \"t+=+%28-b%29%2F%282a%29\" when
\n" ); document.write( "equation is in the form \"+ax%5E2+%2B+bx+%2B+c+=+0\"
\n" ); document.write( "\"a+=+-4.9\"
\n" ); document.write( "\"b+=+192\"
\n" ); document.write( "\"t+=+%28-192%29+%2F+%28-9.8%29\"
\n" ); document.write( "\"t+=+19.592\" sec (this is exactly 1/2 the time to hit the ground)
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\n" ); document.write( "(3) I need to find \"h%5Bt%5D\" when \"t+=+19.592\"
\n" ); document.write( "\"h%5Bmax%5D+=+-4.9t%5E2+%2B+192t\"
\n" ); document.write( "\"h%5Bmax%5D+=+-4.9%2A%2819.592%29%5E2+%2B+192%2A%2819.592%29\"
\n" ); document.write( "\"h%5Bmax%5D+=+-1880.848+%2B+3761.664\"
\n" ); document.write( "\"h%5Bmax%5D+=+1880.816\" ft (this agrees with graph, also)
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