document.write( "Question 712328: A car travels along a straight line at a constant speed of 62.5 mi/h for a distance d and then another distance d in the same direction at another constant speed. The average velocity for the entire trip is 32.5 mi/h. \r
\n" ); document.write( "\n" ); document.write( "I don't get how to set up this problem at all.. \n" ); document.write( "

Algebra.Com's Answer #437871 by stanbon(75887) $\"\"$ $\"About$

You can put this solution on YOUR website!
A car travels along a straight line at a constant speed of 62.5 mi/h for a distance d and then another distance d in the same direction at another constant speed. The average velocity for the entire trip is 32.5 mi/h.
\n" ); document.write( "============
\n" ); document.write( "1st leg DATA:
\n" ); document.write( "distance = d miles ; rate = 62.5 mph ; time = d/r = d/62.5 hours
\n" ); document.write( "-----
\n" ); document.write( "2nd leg DATA:
\n" ); document.write( "distance = d miles ; rate = r mph ; time = d/r hrs
\n" ); document.write( "--------
\n" ); document.write( "Equation:
\n" ); document.write( "average speed = (total distance)/(total time) = (2d miles)/[(d/62.5)+(d/r)]
\n" ); document.write( "----
\n" ); document.write( "(2d)/[rd+62.5d)/(62.5r)] = 32.5 mph
\n" ); document.write( "---
\n" ); document.write( "(125rd = 32.5[rd+62.5d]
\n" ); document.write( "125rd = 32.5rd + 2031.25d
\n" ); document.write( "92.5rd - 2031.25d = 0
\n" ); document.write( "etc.
\n" ); document.write( "============
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "

\n" );