document.write( "Question 350545: A car travels at 60 mph east for 20 min then at 30 mph north for 30 min. What is the average speed and average velocity? \n" ); document.write( "
Algebra.Com's Answer #250658 by Fombitz(32388)\"\" \"About 
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Rate*Time=Distance
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\n" ); document.write( "Find the total distance traveled.
\n" ); document.write( "\"60%281%2F3%29=20\" miles East
\n" ); document.write( "\"30%281%2F2%29=15\" miles North
\n" ); document.write( "\"D%5Bt%5D=20%2B15\"
\n" ); document.write( "\"D%5Bt%5D=35\"miles
\n" ); document.write( "Find the total time elapsed,
\n" ); document.write( "\"t=1%2F3%2B1%2F2=5%2F6\"hr
\n" ); document.write( "Average speed is distance traveled divided by time elapsed.
\n" ); document.write( "\"V%5Bave%5D=35%2F%286%2F5%29=42\"mph
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\n" ); document.write( "Average velocity is the change in the position vector divided by elapsed time.
\n" ); document.write( "(\"0\",\"0\") is the starting point.
\n" ); document.write( "East is positive \"x\".
\n" ); document.write( "North is positive \"y\".
\n" ); document.write( "Determine the final position.
\n" ); document.write( "(\"0\",\"0\")+(\"20\",\"0\")+(\"0\",\"15\")=(\"20\",\"15\")
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\n" ); document.write( "The magnitude of the position vector is \"V%5E2=20%5E2%2B15%5E2=625\"
\n" ); document.write( "\"abs%28X%29=25\" miles
\n" ); document.write( "Divide by elapsed time,
\n" ); document.write( "\"abs%28V%29=25%2F%285%2F6%29\"
\n" ); document.write( "\"abs%28V%29=30\" mph
\n" ); document.write( "The direction is given by
\n" ); document.write( "\"tan%28theta%29=15%2F20\" where theta is the angle measured CCW from the x-axis.
\n" ); document.write( "\"theta=36.9\" degrees
\n" ); document.write( "The velocity vector has magnitude \"30\" mph and angle of \"36.9+\"degrees or in vector coordinates (\"24\",\"18\") mph.
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