document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=397241>Question 397241</A>: <I><SPAN STYLE=\"word-break: break-all;\"> This is a quadratic function question but I didn't see that as an option to select.\r<BR>\n" );
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document.write( "A ball is tossed straight up from the top of a 1,127 foot tall building with an initial speed of 44 feet per second.  The height h(t) of the ball t seconds after it is thrown is given by h(t)= -16t^2 + at + b (t^2 is my way of saying t-squared), where a is the initial speed of the ball and b is the initial height from which it is thrown.\r<BR>\n" );
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document.write( "A. How long was the ball in the air before it hit the street below?  The answer is 9.88 seconds but I can't figure out how to get to the answer. I set it up as follows:\r<BR>\n" );
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document.write( "h(t)= -16t^2 + 44t + 1127\r<BR>\n" );
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document.write( "B. What is the maximum height the ball reaches?  Answer is 1157.25 feet- again not sure how to get this.\r<BR>\n" );
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document.write( "C. How long does it take the ball to reach its maximum height?  Answer is 1.37 seconds.\r<BR>\n" );
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document.write( "Even if you can just help with letter A. that would be a huge help.\r<BR>\n" );
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document.write( "Thank You </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #281621 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=281621\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A. How long was the ball in the air before it hit the street below? The answer is 9.88 seconds but I can't figure out how to get to the answer. I set it up as follows: <BR>\n" );
document.write( "h(t)= -16t^2 + 44t + 1127<BR>\n" );
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document.write( "h(t) is the height of the ball after t seconds.<BR>\n" );
document.write( "The height is zero when the ball is back on the ground.<BR>\n" );
document.write( "Solve: -16t^2 + 44t + 1127 = 0<BR>\n" );
document.write( "Use the quadratic formula to get:<BR>\n" );
document.write( "t = [-44 +- sqrt(44^2-4*-16*1127)]/(-32)<BR>\n" );
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document.write( "To get the positive solution:<BR>\n" );
document.write( "t = [-44 - sqrt(74064)]/(-32)<BR>\n" );
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document.write( "t = [-44-272.15]/(-32)<BR>\n" );
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document.write( "t = 9.88 seconds<BR>\n" );
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document.write( "  <BR>\n" );
document.write( "B. What is the maximum height the ball reaches? Answer is 1157.25 feet- again not sure how to get this.<BR>\n" );
document.write( "Max height occurs when x = -b/(2a) = -44/(2*-16) = 1.375 seconds<BR>\n" );
document.write( "Max height at that time is h(1.375) <BR>\n" );
document.write( "h(1.375) = -16(1.375)^2+44(1.375)+1127 = 1157.3 feet<BR>\n" );
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document.write( "C. How long does it take the ball to reach its maximum height? Answer is 1.37 seconds.<BR>\n" );
document.write( "Answered above.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. <BR>\n" );
document.write( " </SPAN>\n" );
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