document.write( "Question 1097946: An astronaut on the moon throws a baseball upward. The astronaut is 6 fee, 6 inches tall and the initial velocity of the ball is 30 feet per second. The height of the ball is approximated by the function \r
\n" ); document.write( "\n" ); document.write( "s(t)= -2.7t^2 + 30t + 6.5,\r
\n" ); document.write( "\n" ); document.write( "where t is the number of seconds after the ball was thrown.\r
\n" ); document.write( "\n" ); document.write( "(a) After how many seconds is the ball 12 feet above the moon’s surface?
\n" ); document.write( "(b) How many seconds after it was thrown will the ball return to the surface?
\n" ); document.write( "(c) The ball will never reach a height of 100 feet. How can this be determined analytically? \n" ); document.write( "

Algebra.Com's Answer #712380 by ikleyn(52781) $\"\"$ $\"About$

You can put this solution on YOUR website!
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\n" ); document.write( "An astronaut on the moon throws a baseball upward. The astronaut is 6 fee, 6 inches tall and the initial velocity
\n" ); document.write( "of the ball is 30 feet per second. The height of the ball is approximated by the function \r
\n" ); document.write( "\n" ); document.write( "s(t)= -2.7t^2 + 30t + 6.5,\r
\n" ); document.write( "\n" ); document.write( "where t is the number of seconds after the ball was thrown.\r
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document.write( "(a)  After how many seconds is the ball 12 feet above the moon’s surface?\r\n" );
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document.write( "     To get the answer, solve this quadratic equation\r\n" );
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document.write( "     -2.7t^2 + 30t + 6.5 = 12.\r\n" );
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document.write( "      Find its two roots. They are your solutions.\r\n" );
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document.write( "(b) How many seconds after it was thrown will the ball return to the surface?\r\n" );
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document.write( "     To get the answer, solve this quadratic equation\r\n" );
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document.write( "     -2.7t^2 + 30t + 6.5 = 0.\r\n" );
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document.write( "      Find its two roots. The positive root will be your solutions.\r\n" );
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document.write( "(c) The ball will never reach a height of 100 feet. How can this be determined analytically?\r\n" );
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document.write( "     Find the vertex of the given quadratic function.\r\n" );
document.write( "     It will give you the maximum value of the function, which is the maximum height.\r\n" );
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document.write( "     On how to do it, see the lessons\r\n" );
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document.write( "         - HOW TO complete the square to find the minimum/maximum of a quadratic function\r\n" );
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document.write( "         - Briefly on finding the minimum/maximum of a quadratic function\r\n" );
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document.write( "        - HOW TO complete the square to find the vertex of a parabola\r\n" );
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document.write( "        - Briefly on finding the vertex of a parabola\r\n" );
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document.write( "    in this site.\r\n" );
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\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 \"Finding minimum/maximum of quadratic functions\". \r
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\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Save the link to this online textbook together with its description\r
\n" ); document.write( "
\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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