document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=217218>Question 217218</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A projectile is fired directly upward with a muzzle velocity of 860 feet per second from a height of 7 feet above the ground.\r<BR>\n" );
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document.write( "a. Determine a function for the height of the projectile t seconds after it's released.\r<BR>\n" );
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document.write( "b. How long does it take the projectile to reach of height of 100 feet on its way up?\r<BR>\n" );
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document.write( "c. How long is the projectile in the air? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #163820 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=163820\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A projectile is fired directly upward with a muzzle velocity of 860 feet per<BR>\n" );
document.write( " second from a height of 7 feet above the ground.<BR>\n" );
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document.write( "a. Determine a function for the height of the projectile t seconds after it's released.<BR>\n" );
document.write( "Assuming the equation: h = -16t^2 + vt + c<BR>\n" );
document.write( "h = -16t^2 + 860t + 7<BR>\n" );
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document.write( "b. How long does it take the projectile to reach of height of 100 feet on its way up?<BR>\n" );
document.write( "-16^2 + 860t + 7 = 100<BR>\n" );
document.write( "-16t^2 + 860t + 7 - 100 = 0<BR>\n" );
document.write( "-16t^2 + 860t - 93 = 0<BR>\n" );
document.write( "Use the quadratic formulas to find t<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+ ALIGN=MIDDLE  ALT=\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "In this equation: x = t: a=-16; b=860; c=-93<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t+=+%28-860+%2B-+sqrt%28+860%5E2+-+4+%2A+-16+%2A+-93+%29%29%2F%282%2A-16%29+ ALIGN=MIDDLE  ALT=\"t+=+%28-860+%2B-+sqrt%28+860%5E2+-+4+%2A+-16+%2A+-93+%29%29%2F%282%2A-16%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Do the math here and you get: t =.108 seconds for 100' on the way up <BR>\n" );
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document.write( "c. How long is the projectile in the air?<BR>\n" );
document.write( "h = 0, the equation for this -16t^2 + 860t + 7 = 0<BR>\n" );
document.write( "Use the quadratic formulas to find t<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+ ALIGN=MIDDLE  ALT=\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "In this equation: x = t: a=-16; b=860; c=7<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t+=+%28-860+%2B-+sqrt%28+860%5E2+-+4+%2A+-16+%2A+7+%29%29%2F%282%2A-16%29+ ALIGN=MIDDLE  ALT=\"t+=+%28-860+%2B-+sqrt%28+860%5E2+-+4+%2A+-16+%2A+7+%29%29%2F%282%2A-16%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Do the math here and you get: t = 53.758 seconds to return to earth </SPAN>\n" );
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