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mathmaniac
Active member
 Mar 4, 2013
 188
The system is in equlibrium,find T1 and explain.
Thanks.
Thanks.
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On the sketch I'm going to call m1 = 4 kg and m2 = 6 kg. I'm also going to deal with the two masses as separate systems. I am defining upward as +y in both diagrams.Modified it.
My work?
I can see nothing is moving,so I conclude
4g+6g=T1+T
where g is acceleration due to gravity
I don't see anyway to go further.
how can it be when some other forces like 4g and T1 are pulling T?For m1:
Using Newton's 2nd I get T1  T  m1*g = 0, so we get an equation for T1 in terms of T.
For m2:
Using Newton's 2nd I get m2*g + T = 0
Things on the one side of the pulley have no effects on the other?I'm also going to deal with the two masses as separate systems.
I got my T1's and T's reversed. This should read T  T1  m1*g = 0For m1:
Using Newton's 2nd I get T1  T  m1*g = 0, so we get an equation for T1 in terms of T.
Yes, that's the correct answer.T=6g and T1=6g+4g=10g
But this is not the answer I had been taught,it is 2g.
They do correlate...through the tension T.Things on the one side of the pulley have no effects on the other?
"Ideal" pulleys do nothing more than change the direction of the tension. You can straighten them out but note when you do that the weight of the mass on the left is to the left, and the weight of the mass on the right is to the right. It is for this reason I prefer not to teach my classes about it...the concepts can get a bit confusing when all the forces get laid down into one line.Please demonstrate how it would be like when the string is laid out in a straight line.
Thanks
Regards