document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=189179>Question 189179</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/9780618851881/algebrahomeworkh>College Algebra A Graphing Approach</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> #82 Sports<BR>\n" );
document.write( "You throw a baseball straight up into the air at a velocity of 45 feet per second. You release the baseball at a height of 5.5 feet and catch it when it falls back to a height of 6 feet.\r<BR>\n" );
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document.write( "a. Use the position equation to write a mathematical model for the height of the baseball.\r<BR>\n" );
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document.write( "b. Find the height of the baseball after 0.5 seconds.\r<BR>\n" );
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document.write( "c. How many seconds is the baseball in the air? Use a graphing utility to verify your answer. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #141938 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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/cgi-bin/show-face.mpl?user=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=141938\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> You throw a baseball straight up into the air at a velocity of 45 feet per second. You release the baseball at a height of 5.5 feet and catch it when it falls back to a height of 6 feet. <BR>\n" );
document.write( "a. Use the position equation to write a mathematical model for the height of the baseball. <BR>\n" );
document.write( "y = -16t^2 + 45t + 5.5 at any time t.  y in feet, t in seconds<BR>\n" );
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document.write( "b. Find the height of the baseball after 0.5 seconds.<BR>\n" );
document.write( "Sub 0.5 into the equation<BR>\n" );
document.write( "y = -16*0.25 + 45*0.5 + 5.5<BR>\n" );
document.write( "y = -4 + 22.5 + 5.5<BR>\n" );
document.write( "y @ 0.5 = 24 feet<BR>\n" );
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document.write( "c. How many seconds is the baseball in the air? Use a graphing utility to verify your answer.<BR>\n" );
document.write( "Find the times when the ball is at 6 feet.  There are 2 of them, 1 going up, 1 coming down.<BR>\n" );
document.write( "6 = -16t^2 + 45t + 5.5<BR>\n" );
document.write( "16t^2 - 45t + 0.5 = 0<BR>\n" );
document.write( "t = (45/32) - sqrt(1993)/32 (going up) and<BR>\n" );
document.write( "t = (45/32) + sqrt(1993)/32 (coming down)<BR>\n" );
document.write( "t = ~ 2.801 seconds<BR>\n" );
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document.write( "The graph looks good.<BR>\n" );
document.write( " </SPAN>\n" );
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