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Tension question

  • Thread starter tristan_fc
  • Start date
12
0
I believe that I was late the day my instructor explained this type of problem in class, and my textbook is worthless, so I thought I would give this a shot. It's just a tension problem, but I don't know for sure how to do it.

A 9.00 kg handing weight is connected by a string over a pulley to a 5.00 kg block that is sliding on a flat table. If the coefficient of kinetic friction is 0.187, find the tension in the string.

I believe that tension is the sum of all forces on the rope correct? I recall my teacher saying that we could turn a similar problem into a problem on the X-axis by making gravity a force pulling on the block in the x-direction. Anyway, I thought that I would just do 9*9.8+-(5*0.187), but that didn't seem right to me because it would seem that a frictional force would increase the tension and not decrease it? I appreciate any help.

-Tristan
 
12
0
eh... I posted my question in the wrong section and they moved it here. I'm actually in Engineering Physics I in college, but I guess it doesn't matter where the question is if I get help.
 

HallsofIvy

Science Advisor
Homework Helper
41,712
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Yes, frictional force would increase tension, not decrease it.
However, if there were NO friction force, there would be NO tension on the rope, not the "9*9.9" you have. If there were no friction force the block would move freely. The tension on the rope IS the friction force.
 

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