document.write( "Question 1089226: A pulley is suspended from the ceiling by a string by a string 30.2cm long .THe distance from the ceiling to the pulley is 13.7 cm .determine the diameter of the pulley . \n" ); document.write( "
Algebra.Com's Answer #703567 by jim_thompson5910(35256) ![]() You can put this solution on YOUR website! \n" ); document.write( "Refer to the figure below\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \r\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "As you can see, the string can be broken into three parts:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "I'm going to make the assumption that AB = DE. In other words, I'm assuming that the pulley is held such that the string falling on each side is the same length and that the end of one string is perfectly level with the other end.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "If this assumption is held true, then we know that \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "AB = 13.7 and DE = 13.7 (since AB = DE)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So far AB+DE = 13.7+13.7 = 27.4 cm of string is used for the straight portions (section I and section III). \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The string is 30.2cm long. Therefore that leaves 30.2-27.4 = 2.8 cm for the curved red section\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-------------------------------------------\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "That curved red section (section II) is a semi-circle. It is exactly halfway around the distance of the full circle. \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Double the value 2.8 to get 5.6\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The circumference of the circle is 5.6 cm\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So C = 5.6 will be used to find the diameter d\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "C = pi*d \n" ); document.write( "pi*d = C \n" ); document.write( "pi*d/pi = C/pi \n" ); document.write( "d = C/pi \n" ); document.write( "d = 5.6/pi \n" ); document.write( "d = 1.78253536262922\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The diameter of the pulley is roughly 1.7825 cm\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |