What Is the Tension in the Left Rope When a Person Sits on a Supported Beam?

AI Thread Summary
A 10-meter uniform beam weighing 100 N is supported by two ropes, and a 400 N person sits 2 meters from the left end. The initial calculation for the tension in the left rope was incorrect, as the correct tension is 370 N. Additionally, when holding a 6 N book at rest above the head, the net force on the book is 0 N, despite the force exerted by the head being 6 N. The discussion highlights the importance of correctly applying equilibrium principles in static scenarios. Understanding these concepts is crucial for solving similar physics problems effectively.
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Homework Statement


A 10-m uniform beam of weight 100 N is supported by two ropes at its ends. If a 400 N person sits at 2.0 m from the left end of the beam, what is the tension in the left rope?

I thought the answer would be:

The Attempt at a Solution


100*5 + 400*7 = T*10
3300 = T*10

T = 330 N

But it's not correct. What am I doing wrong?

Also:
A book weighs 6 N. When held at rest above your head the net force on the book is? I say -6 N. Is this correct?

Thanks!
 
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Ah simple math error. It's 370.
Any feedback for the other question? I have another topic about the same subject that is actually more urgent. Thanks!
 
-6 sounds like a good answer?
 
The force exerted by your head on the book is 6 N. I would not call this the net force though. The net force on the book is 0 because it is *at rest*.
 
ya i think you are right
 

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