Physics Help Forum Which of the following machines have the same Ideal Mechanical Advantage?

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 Jun 16th 2009, 12:15 PM #1 Senior Member   Join Date: Mar 2009 Posts: 129 Which of the following machines have the same Ideal Mechanical Advantage? PHYSICS 534 Can someone please explain Exam 2006 #9 to me? I get why 4 is IMA = 5 and that 1 is IMA = 4 however what I do not understand is why 2 is IMA = 5 and what is 3? Any help would be greatly appreciated! Thanks in advance! EDIT: *I POSTED IN WRONG PLACE BY ACCIDENT. IF A MODERATOR COULD MOVE IT IN THE RIGHT PLACE, THAT'D BE NICE.* Last edited by s3a; Jun 16th 2009 at 12:18 PM.
Jun 16th 2009, 06:56 PM   #2
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 Originally Posted by s3a PHYSICS 534 Can someone please explain Exam 2006 #9 to me? I get why 4 is IMA = 5 and that 1 is IMA = 4 however what I do not understand is why 2 is IMA = 5 and what is 3? Any help would be greatly appreciated! Thanks in advance! EDIT: *I POSTED IN WRONG PLACE BY ACCIDENT. IF A MODERATOR COULD MOVE IT IN THE RIGHT PLACE, THAT'D BE NICE.*
In a single fixed pulley,IMA= 1. In a single movable pulley IMA = 2.
So in 1 you have to take 4 segments of string and in 2 you have to take 5 segments.
In 3 IMA = distance moved by the effort/ distance moved by the load
= (15^2 + 3^2)^1/2/3