document.write( "Question 346023: It takes 12 seconds for two trains to pass one another when moving in opposite directions. If they are in the same direction, it will take the faster train 3 minutes to pass the slower one. If the trains are 130 meters and 120 meters long, respectively, what are the rates of the two trains? \n" ); document.write( "
Algebra.Com's Answer #247555 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! It takes 12 seconds for two trains to pass one another when moving in opposite directions. \n" ); document.write( " If they are in the same direction, it will take the faster train 3 minutes to pass the slower one. \n" ); document.write( " If the trains are 130 meters and 120 meters long, respectively, what are the rates of the two trains? \n" ); document.write( ": \n" ); document.write( "Let a = speed of the faster train \n" ); document.write( "let b = speed of the slower \n" ); document.write( ": \n" ); document.write( "Trains meeting each other \n" ); document.write( "The sum of the speed of the two trains (in meters/sec) \n" ); document.write( "speed = dist/time \n" ); document.write( "a + b = \n" ); document.write( "a + b = 20.83 m/sec is the sum of their speeds \n" ); document.write( ": \n" ); document.write( "Trains going in the same direction (change 3 min to 180 sec \n" ); document.write( "a - b = \n" ); document.write( "a - b = 1.39 m/sec is the difference of their speed \n" ); document.write( ": \n" ); document.write( "Use elimination \n" ); document.write( "a + b = 20.83 \n" ); document.write( "a - b = 1.39 \n" ); document.write( "----------------adding eliminates b, find a \n" ); document.write( "2a = 22.22 \n" ); document.write( "a = \n" ); document.write( "a = 11.11 m/sec is the speed of train a \n" ); document.write( "In km/hr: \n" ); document.write( ": \n" ); document.write( "then using the sum equation find b \n" ); document.write( "11.11 + b = 20.83 \n" ); document.write( "b = 20.83 - 11.11 \n" ); document.write( "b = 9.72 m/sec is the speed of train b \n" ); document.write( "In km/hr \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |