document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=123536>Question 123536</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0073268623/algebrahomeworkh>Elementary and intermediate Algebra</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> Skydiving. If there were no air resistance, then the height (in feet) above the earth for a skydiver t seconds after jumping from an airplane at 10,000 feet would be given by  h(t)= -16t^2 + 10,000\r<BR>\n" );
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document.write( "a) find the time that it would take to fall to earth with no air resistance: that is, find t for which (t)= 0.A skydiveractually gets about twice as much free fall time due to air resistance.\r<BR>\n" );
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document.write( "b)Use the accompanying graph to determine whether the skydiver(with no air resistance ) falls farther in the first 5 seconds or the last 5 seconds of the fall.\r<BR>\n" );
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document.write( "c) Is the skydiver's velocity increasing or decreasing as she falls? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #90622 by </B><A HREF=/tutors/aboutme.mpl?userid=rajagopalan><B>rajagopalan(174)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=rajagopalan><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=rajagopalan><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=90622\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Part aaa.<BR>\n" );
document.write( "Skydiving. <BR>\n" );
document.write( "height (in feet) above the earth=h(t)= -16t^2 + 10,000<BR>\n" );
document.write( "the time it would take to fall when  h is 0 <BR>\n" );
document.write( "-16t^2 + 10,000=0<BR>\n" );
document.write( "-16t^2=-10000<BR>\n" );
document.write( "16t^2=10000<BR>\n" );
document.write( "t^2=10000/16=625<BR>\n" );
document.write( "t=sqrt 625=25 seconds<BR>\n" );
document.write( "okay\r<BR>\n" );
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document.write( "Part bbb)Use the accompanying graph to determine whether the skydiver(with no air resistance ) falls farther in the first 5 seconds or the last 5 seconds of the fall.\r<BR>\n" );
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document.write( "Though no graph is given we can calculate this:<BR>\n" );
document.write( "Fall distance in first 5 sec =-16t^2 =-16(5*5)=-16*25=-400 m =400 m <BR>\n" );
document.write( "Fall distance in  Last 5 sec =ht after 25 sec-ht after 20 sec<BR>\n" );
document.write( "ht after 25 sec=-16t^2 + 10,000=-16(25*25)+10000=-10000+10000=0<BR>\n" );
document.write( "ht after 20 sec=-16t^2 + 10,000=-16(20*20)+10000=- 6400+10000=3600 m\r<BR>\n" );
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document.write( "So in the Last 5 secs he falls thro 3600 m as against 400m in the first 5 secs.\r<BR>\n" );
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document.write( "Part ccc) Is the skydiver's velocity increasing or decreasing as she falls?\r<BR>\n" );
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document.write( "Mean Velocity in first 5 secs =dist/time=400/5=80 m/sec<BR>\n" );
document.write( "Mean Velocity in Last  5 secs =dist/time=3600/5=720 m/sec<BR>\n" );
document.write( "Obviously Velocity is increasing.\r<BR>\n" );
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document.write( "In fact he is accelerating.<BR>\n" );
document.write( "Note : Ignore the signs for distance as descending is shown as negative.<BR>\n" );
document.write( "Cheers<BR>\n" );
document.write( "good day </SPAN>\n" );
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