Unit Vector Question. *updated*

[imapeiceofwod]

OK here's the problem. I am completely unsure how to solve it my teacher never even did an example like this before.

The total force exerted on the top of the mast B by the sailboat's forestay AB and backstay BC is 180i- 820j (N). What are the magnitudes of the forces exerted at B by the cables AB and BC?

A(0,1.2)
B(4,13)
C(9,1)

Any help please and thank you

here's what i got so far. I drew i diagram of the situation drawing and drew the vectors. I figured out Fab=(4i,11.8j) and Fbc=(5i,-12j)

Then i found the total force in the i direction which is 9i and the total force in the j which is 0.2j .

I know that the total force in the i direction is suppose to be 180i but i got 9i for the total force. Any help?

 

[Quinzio]

Since you have to achieve 180i- 820j (N) it seems rather odd your vectors are (4i,11.8j) +(5i,-12j).

Would you mind showing us the drawing with the vectors and the backstay/forestay ?

 

[imapeiceofwod]

heres the picture

 

[Quinzio]

Ok, but I don't see the force vector acting on B.

AB and BC are basically ropes, so they're pulling or pushing B ? (I ask this looking at how you drew the arrows)

 

[imapeiceofwod]

im sry, i drew the vector CB its suppose to be BC

 

[Quinzio]

don't mind, but draw the vector of the total force on B ...