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## Homework Statement

From http://library.thinkquest.org/10796/index.html (#6b, 6c)

The site accepts the answer 49N for #6c, but I'm not sure why.A 10 kg picture is hanging on a wall by two ropes.

http://library.thinkquest.org/10796/ch5/IMG00008.GIF

...

b. Are the forces acting on the ropes A and B equal in magnitude?

c. How big is the force acting on the rope A?

## Homework Equations

[tex]F_g=mg[/tex]

[tex]F=\sqrt{F_x^2+F_y^2}[/tex]

[tex]F_x=F\times \cos \theta[/tex]

## The Attempt at a Solution

The answer for #6c appears to be equal to

[tex]10\textrm{kg}\times 9.80\textrm{m/s}^2\times \textrm{cos }60^\circ=49\textrm{N,}[/tex]

but that doesn't make sense to me; shouldn't we combine the weight of the picture with the rightward pull? In that case, how do we find the rightward pull?

Or, is there an imaginary diagonal force--equal in magnitude to the gravitational force--of which we want the horizontal component? In that case, why?

The answer to #6b is "No," but I'm not sure why. (I'm guessing that once I understand #6c, then #6b will follow.)

Thank you!

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