document.write( "Question 414299: The frequency or number (f) of vibration of a string under constant tension is inversely proportional to the length (l) of the string. If a string of 48 cm
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document.write( "vibrates 192 cycles per second, find the the constant of proportionality and the number of vibrations per second a string of 32 cm will make. \n" );
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Algebra.Com's Answer #290613 by Theo(13342)![]() ![]() You can put this solution on YOUR website! direct and inverse proportion formulas are shown below:\r \n" ); document.write( "\n" ); document.write( "y = k*x (direct proportion)\r \n" ); document.write( "\n" ); document.write( "y = k/x (inverse proportion)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Since you are dealing with inverse proportion, then the second formula applies.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "k is the constant of proportionality.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you are given that a string of 48 cm vibrates 192 cycles per second.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you can use this fact to find the constant of proportionality.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "let y = number of cycles per second. \n" ); document.write( "let x = length of the string.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "y = k/x becomes 192 = k/48\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "multiply both sides of this equation by 48 to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "k = 192 * 48 = 9216\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "that's your constant of proportionality.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you apply that constant of proportionality when x = 32 cm.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you get y = 9216 / 32 = 288\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the string will vibrate 288 cycles per second when the length of the string is 32 cm.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you can see that the proportion is inverse because, as the string length increases, the number of vibrations per second decreases.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you can also see that the ratio of the short string to the long string is inversely proportional as shown in the following table.\r \n" ); document.write( "\n" ); document.write( " \r\n" ); document.write( "\r\n" ); document.write( "long string short string ratio of short string to long string\r\n" ); document.write( "\r\n" ); document.write( "l = 48 l = 32 32/48 = 2/3\r\n" ); document.write( "\r\n" ); document.write( "vbs = 192 vbs = 288 288/192 = 3/2\r\n" ); document.write( "\r\n" ); document.write( "\r \n" ); document.write( "\n" ); document.write( "l = length \n" ); document.write( "vbs = vibrations per second\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |