document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=158862>Question 158862</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 1. two cars enter a Florida Turnpike at 8:00am, each heading for Wildwood. one car average speed is 10 miles per hour more than the other. The faster car arrives at Wildwood at 11:00am, 1/2 hours before the other car. What is the average speed of each car? How far did each travel.\r<BR>\n" );
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document.write( "2. Am object is propelled upward with an initial velocity of 20 meters per second. The distance, in meter, of the object from the ground after t seconds is s=-4.9t+20t.<BR>\n" );
document.write( "a. when will the object be 15 meters above the ground?<BR>\n" );
document.write( "b. when will it strike the ground?<BR>\n" );
document.write( "c. will the object reach a height of 100 meters? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #117088 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=117088\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 1. two cars enter a Florida Turnpike at 8:00am, each heading for Wildwood. one car average speed is 10 miles per hour more than the other. The faster car arrives at Wildwood at 11:00am, 1/2 hours before the other car. What is the average speed of each car? How far did each travel.<BR>\n" );
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document.write( "Fast car travel time = 3 hrs<BR>\n" );
document.write( "Slow car travel time = 3.5 hrs<BR>\n" );
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document.write( "Let s = speed of the slower car<BR>\n" );
document.write( "then<BR>\n" );
document.write( "(x+10) = speed of the faster car<BR>\n" );
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document.write( "Both cars traveled the same distance, write a distance equation<BR>\n" );
document.write( "Dist = time * speed<BR>\n" );
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document.write( "slow car dist = fast car dist<BR>\n" );
document.write( "3.5s = 3(s+10)<BR>\n" );
document.write( "3.5s = 3s + 30<BR>\n" );
document.write( "3.5s - 3s = 30<BR>\n" );
document.write( ".5s = 30<BR>\n" );
document.write( "s = 60 mph is the slow car<BR>\n" );
document.write( "and<BR>\n" );
document.write( "60 + 10 = 70 mph is the speed of the fast car<BR>\n" );
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document.write( "Find the dist using the slow car expression<BR>\n" );
document.write( "3.5 * 60 = 210 mi<BR>\n" );
document.write( "Check solutions by finding the dist using the fast car expression<BR>\n" );
document.write( "3 * 70 = 210 mi<BR>\n" );
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document.write( "2. Am object is propelled upward with an initial velocity of 20 meters per second. The distance, in meter, of the object from the ground after t seconds is s=-4.9t+20t. I think this should be -4.9t^2 + 20t<BR>\n" );
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document.write( "a. when will the object be 15 meters above the ground?<BR>\n" );
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document.write( "-4.9t^2 + 20t = 15<BR>\n" );
document.write( "-4.9t^2 + 20t - 15 = 0<BR>\n" );
document.write( "Use the quadratic formula, we get two positive solutions:<BR>\n" );
document.write( "t ~ 1 sec (on the way up)<BR>\n" );
document.write( "and<BR>\n" );
document.write( "t ~ 3.1 (on the way down)\r<BR>\n" );
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document.write( "b. when will it strike the ground?<BR>\n" );
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document.write( "When it strikes the ground, s = 0<BR>\n" );
document.write( "-4.9t^2 + 20t = 0<BR>\n" );
document.write( "-t(4.9t - 20) = 0<BR>\n" );
document.write( "4.9t - 20 = 0<BR>\n" );
document.write( "4.9t = +20<BR>\n" );
document.write( "t = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=20%2F4.9 ALIGN=MIDDLE  ALT=\"20%2F4.9\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "t = 4.1 sec<BR>\n" );
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document.write( "c. will the object reach a height of 100 meters?<BR>\n" );
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document.write( "Obviously it won't, max will occur around 2 sec<BR>\n" );
document.write( "h = -4.9(2^2) + 20(2)<BR>\n" );
document.write( "h = -19.6 + 40 = 20.4 ft, not even close </SPAN>\n" );
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