document.write( "Question 1149626: The middle of a uniform 80cm long bar is placed on a knife edge and a 4kg mass is suspended from one free end of the bar. How far from the other free end must a 6.4kg mass be suspended to maintain the bar horizontal position? \n" ); document.write( "

Algebra.Com's Answer #771237 by ikleyn(52781) $\"\"$ $\"About$

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document.write( "In this simple case, the equilibrium condition states that the product of the weight by the length of the arm \r\n" );
document.write( "should be same for each side.\r\n" );
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document.write( "It gives the equation\r\n" );
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document.write( "    40 cm * 4 kg = x cm * 6.4 kg\r\n" );
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document.write( "From the equation,  x =  = 25.\r\n" );
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document.write( "So, the mass of 6.4 kg should be suspended at 25 cm from the middle of the bar,\r\n" );
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document.write( "i.e. in  40 - 25 = 15 cm from its other end.    ANSWER\r\n" );
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\n" ); document.write( "\n" ); document.write( "People know this equilibrium condition just many thousand years.\r
\n" ); document.write( "\n" ); document.write( "Its clear mathematical formulation is attributed to Archimedes (law of lever).\r
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\n" ); document.write( "\n" ); document.write( "See the lesson\r
\n" ); document.write( "\n" ); document.write( " - Using proportions to solve word problems in Physics \r
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