document.write( "Question 1174255: A model rocket is launched from the roof of a building. Its flight path through the air is modelled by h(t)=-5t2+30t+10, where h(t) is the height of the rocket above the ground in metres and t is the time after launch in seconds. I've done all the questions for this question, except these two.\r
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Algebra.Com's Answer #799676 by ikleyn(52797)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "The height of the building is the constant term of the given quadratic function.\r\n" );
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document.write( "Indeed, it is the height, where the \"model rocket\" starts at t= 0.\r\n" );
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document.write( "Substitute t= 0 into the formula for the height, and you will get  h(0) = 10 meters.\r\n" );
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document.write( "To answer this question, solve this quadratic equation\r\n" );
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document.write( "    -5t^2 + 30t + 10 = 45  meters.\r\n" );
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document.write( "You will get two solutions for \"t\": one works for the rocket moving up, while the other works for falling rocket.\r\n" );
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\n" ); document.write( "\n" ); document.write( "To learn everything about this class of problems, look into the lessons\r
\n" ); document.write( "\n" ); document.write( "    - Introductory lesson on a projectile thrown-shot-launched vertically up \r
\n" ); document.write( "\n" ); document.write( "    - Problem on a projectile moving vertically up and down\r
\n" ); document.write( "\n" ); document.write( "    - Problem on an arrow shot vertically upward\r
\n" ); document.write( "\n" ); document.write( "    - Problem on a ball thrown vertically up from the top of a tower \r
\n" ); document.write( "\n" ); document.write( "    - Problem on a toy rocket launched vertically up from a tall platform\r
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\n" ); document.write( "\n" ); document.write( "Consider these lessons as your textbook,  handbook,  tutorials and  (free of charge)  home teacher.
\n" ); document.write( "Read them attentively and learn how to solve this type of problems once and for all.\r
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\n" ); document.write( "\n" ); document.write( "Also,  you have this free of charge online textbook in ALGEBRA-I in this site\r
\n" ); document.write( "\n" ); document.write( "    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.\r
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\n" ); document.write( "\n" ); document.write( "The referred lessons are the part of this textbook under the topic \"Projectiles launched/thrown and moving vertically up and dawn\".\r
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\n" ); document.write( "\n" ); document.write( "Save the link to this online textbook together with its description\r
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\n" ); document.write( "\n" ); document.write( "Free of charge online textbook in ALGEBRA-I
\n" ); document.write( "https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson\r
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\n" ); document.write( "\n" ); document.write( "to your archive and use it when it is needed.\r
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