document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=189576>Question 189576</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/9780073533490/algebrahomeworkh>Elementary and Intermediate Algebra</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> In 1978 Udo Beyer (East Germany) set a world record in the shot-put of 72 ft 8 in. If Beyer had projected the shot straight upward with a velocity of 30 ft/sec from a height of 5 ft, then for what values of t would the shot be under 15 ft high? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #142263 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=142263\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> In 1978 Udo Beyer (East Germany) set a world record in the shot-put of 72 ft 8 in. If Beyer had projected the shot straight upward with a velocity of 30 ft/sec from a height of 5 ft, then for what values of t would the shot be under 15 ft high?<BR>\n" );
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document.write( "Gravity: -16t^2, upward velocity 30t, initial height: 5'; gives us an equation of:<BR>\n" );
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document.write( "h = -16t^2 + 30t + 5<BR>\n" );
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document.write( "\" for what values of t would the shot be under 15 ft high?\"<BR>\n" );
document.write( "-16t^2 + 30t + 5 < 15<BR>\n" );
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document.write( "-16t^2 + 30t + 5 - 15 = 0<BR>\n" );
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document.write( "-16t^2 + 30t - 10 = 0<BR>\n" );
document.write( "Solve this using the quadratic formula: a=-16; b=30; c=-10<BR>\n" );
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document.write( "You should get two solutions<BR>\n" );
document.write( "t ~ .43 sec<BR>\n" );
document.write( "t ~ 1.44 sec<BR>\n" );
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document.write( "We can say that shot-put was below 15 ft from 0 to .43 sec<BR>\n" );
document.write( "and it was below 15 ft from 1.44 sec until it hit the ground<BR>\n" );
document.write( "Find out when it hit the ground (h=0) using the equation<BR>\n" );
document.write( "-16t^2 + 30t + 5 = 0<BR>\n" );
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document.write( "Use a graph for this, green line represents 15 ft; time (t) on the x axis:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+graph%28+300%2C+200%2C+-1%2C+3%2C+-10%2C+20%2C+-16x%5E2%2B30x%2B5%2C+15%29+ ALIGN=MIDDLE  ALT=\"+graph%28+300%2C+200%2C+-1%2C+3%2C+-10%2C+20%2C+-16x%5E2%2B30x%2B5%2C+15%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "It was below 15 ft from 1.44 sec to approx 2 sec when it hit the ground<BR>\n" );
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document.write( "did this make sense to you? <BR>\n" );
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