document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=150685>Question 150685</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The path of a falling object is given by using the function s= -16t^2+ v sub0 t+ s sub0 where <BR>\n" );
document.write( "v sub0 represents the initial height in ft/sec  and<BR>\n" );
document.write( "s sub0 represents the initial height in feet. <BR>\n" );
document.write( "Also, s represents the height in feet of the object at any time, t which is measured in seconds.\r<BR>\n" );
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document.write( "A. If a rock is thrown upward with an initial velocity of 40 feet per second from the top of a 30 foot building, write the height (s) equation using this information...   <BR>\n" );
document.write( "I got.. -16t^2 + 40t + 30\r<BR>\n" );
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document.write( "B.How high is the rock after 2 seconds?<BR>\n" );
document.write( "I got.. <BR>\n" );
document.write( "s(t)= -16(2)^2 + 40(2) + 30<BR>\n" );
document.write( "s(t)= 46 \r<BR>\n" );
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document.write( "C. After how many seconds will the graph reach maximum height? Show work algebraically.\r<BR>\n" );
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document.write( "D What is the maximum height?\r<BR>\n" );
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document.write( " I need help on C and D... and please tell me if I have figured A and B correctly... Thank you so very much.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #110622 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><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=110622\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Parts A and B are correct.\r<BR>\n" );
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document.write( "C)\r<BR>\n" );
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document.write( "From <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=s%28t%29=-16t%5E2%2B40t%2B30 ALIGN=MIDDLE  ALT=\"s%28t%29=-16t%5E2%2B40t%2B30\"   DISABLED_style= \"max-width:90%; height:auto;\" >, we can see that <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a=-16 ALIGN=MIDDLE  ALT=\"a=-16\"   DISABLED_style= \"max-width:90%; height:auto;\" >, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b=40 ALIGN=MIDDLE  ALT=\"b=40\"   DISABLED_style= \"max-width:90%; height:auto;\" >, and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=c=30 ALIGN=MIDDLE  ALT=\"c=30\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "In order to find out when the rock will reach the max height, use this formula: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=%28-b%29%2F%282a%29 ALIGN=MIDDLE  ALT=\"t=%28-b%29%2F%282a%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=%28-b%29%2F%282a%29 ALIGN=MIDDLE  ALT=\"t=%28-b%29%2F%282a%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > Start with the given formula.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=%28-%2840%29%29%2F%282%28-16%29%29 ALIGN=MIDDLE  ALT=\"t=%28-%2840%29%29%2F%282%28-16%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > Plug in <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a=-16 ALIGN=MIDDLE  ALT=\"a=-16\"   DISABLED_style= \"max-width:90%; height:auto;\" > and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b=40 ALIGN=MIDDLE  ALT=\"b=40\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=%28-40%29%2F%28-32%29 ALIGN=MIDDLE  ALT=\"t=%28-40%29%2F%28-32%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > Multiply 2 and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-16 ALIGN=MIDDLE  ALT=\"-16\"   DISABLED_style= \"max-width:90%; height:auto;\" > to get <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-32 ALIGN=MIDDLE  ALT=\"-32\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=5%2F4 ALIGN=MIDDLE  ALT=\"t=5%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" > Reduce.\r<BR>\n" );
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document.write( "So the rock will reach the max height when <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=5%2F4 ALIGN=MIDDLE  ALT=\"t=5%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=1.25 ALIGN=MIDDLE  ALT=\"t=1.25\"   DISABLED_style= \"max-width:90%; height:auto;\" >. So the rock takes 1.25 seconds to reach the peak.\r<BR>\n" );
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document.write( "D)\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=s%28t%29=-16t%5E2%2B40t%2B30 ALIGN=MIDDLE  ALT=\"s%28t%29=-16t%5E2%2B40t%2B30\"   DISABLED_style= \"max-width:90%; height:auto;\" > Start with the given equation.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=s%285%2F4%29=-16%285%2F4%29%5E2%2B40%285%2F4%29%2B30 ALIGN=MIDDLE  ALT=\"s%285%2F4%29=-16%285%2F4%29%5E2%2B40%285%2F4%29%2B30\"   DISABLED_style= \"max-width:90%; height:auto;\" > Plug in <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=5%2F4 ALIGN=MIDDLE  ALT=\"t=5%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=s%285%2F4%29=-16%2825%2F16%29%2B40%285%2F4%29%2B30 ALIGN=MIDDLE  ALT=\"s%285%2F4%29=-16%2825%2F16%29%2B40%285%2F4%29%2B30\"   DISABLED_style= \"max-width:90%; height:auto;\" > Square <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=5%2F4 ALIGN=MIDDLE  ALT=\"5%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" > to get <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=25%2F16 ALIGN=MIDDLE  ALT=\"25%2F16\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=s%285%2F4%29=-25%2B40%285%2F4%29%2B30 ALIGN=MIDDLE  ALT=\"s%285%2F4%29=-25%2B40%285%2F4%29%2B30\"   DISABLED_style= \"max-width:90%; height:auto;\" > Multiply <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-16 ALIGN=MIDDLE  ALT=\"-16\"   DISABLED_style= \"max-width:90%; height:auto;\" > and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=25%2F16 ALIGN=MIDDLE  ALT=\"25%2F16\"   DISABLED_style= \"max-width:90%; height:auto;\" > to get <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-25 ALIGN=MIDDLE  ALT=\"-25\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=s%285%2F4%29=-25%2B50%2B30 ALIGN=MIDDLE  ALT=\"s%285%2F4%29=-25%2B50%2B30\"   DISABLED_style= \"max-width:90%; height:auto;\" > Multiply <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=40 ALIGN=MIDDLE  ALT=\"40\"   DISABLED_style= \"max-width:90%; height:auto;\" > and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=5%2F4 ALIGN=MIDDLE  ALT=\"5%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" > to get <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=50 ALIGN=MIDDLE  ALT=\"50\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=s%285%2F4%29=55 ALIGN=MIDDLE  ALT=\"s%285%2F4%29=55\"   DISABLED_style= \"max-width:90%; height:auto;\" > Combine like terms.\r<BR>\n" );
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document.write( "So at the peak, the rock is 55 feet high. So the max height is 55 feet. </SPAN>\n" );
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