document.write( "Question 1078882: The force of attraction between two magnets is inversely proportional to the square of the distance between them. When the magnets are r cm apart, the force of attraction between them is F newtons(N). If the distance between the magnets is increased by 400%, the force of attraction between them becomes cF N. Find the value of c.\r
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document.write( "I have solved this but not so sure whether the answer is correct. Please help me with this! Thank you! \n" );
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Algebra.Com's Answer #693276 by Boreal(15235)![]() ![]() You can put this solution on YOUR website! F=k/d^2 \n" ); document.write( "FN=k/r^2 \n" ); document.write( "k=FNr^2 \n" ); document.write( "use k in the second one. \n" ); document.write( "if the distance is increased 400%, then (increase-original amount)/original amount =4, so the new distance is 5 times the first. \n" ); document.write( "cFN=k/(5r)^2, or FNr^2/25r^2, because the 5 has to be squared as well. The new r is 5r, and (5r)^2=25r^2. \n" ); document.write( "cFN=FN/25 \n" ); document.write( "c=1/25 \n" ); document.write( "This is inverse square law \n" ); document.write( "To me, there is some ambiguity in an increase of 400% and the distance is increased four-fold, which would be 1/16. If the two distances were initially 2 cm apart, then a four-fold increase makes them 8 cm apart. That is an (8-2)/2 or a 6/2 % increase or 300%. \n" ); document.write( " |