## anonymous 4 years ago Consider a w-N weight suspended by two wires as shown in the accompanying figure. If the magnitude of the vector F sub 2 is 110 N, find w and the vector F sub 1:

1. anonymous

|dw:1328415051107:dw|

2. anonymous

thats what i am trying to find

3. anonymous

F2 is 110 N as stated in my problem

4. bahrom7893

wait what are u trying to find?

5. anonymous

right, but i need to find w=weight of obejct and magnitude of F sub 1

6. anonymous

physics?

7. anonymous

that is how the problem is written

8. anonymous

i believe a system should solve this, with the understanding f sub 1 + F sub 2=w, cant seem too put it together though

9. anonymous

how about ratio and proportion to find the value of the magnitude of F sub 1|dw:1328416025545:dw| you can find the value of F sub 1. and since you said that F sub 1 + F sub 2=w, plug the values to find weight. . but i'm not sure. .

10. anonymous

what answer do you get for the magnitude of Fsub 1

11. anonymous

|dw:1328416246651:dw| i don't have calculator. .

12. anonymous

i have 124.47 N

13. anonymous

14. anonymous

break it into components. Vector(F1)+vector(f2)+vector(w)=0. Vector f1=magf1<-cos(t1),Sin(t1)> Vector f2=magf2<cos(t2),sin(t2)> X components add to zero -magf1cos(43)+110cos(38)=0 Solve for magf1 and plug into: y components: magf1sin(43)+110sin(38)=w

15. anonymous

and that made me wrong. .lol

16. anonymous

how do the x components add to zero

17. anonymous

instantaneously/or not hah is not in motion. There is no movement in the x direction. Weight is a downward vector so it has no x component. Thus F1 and F2's x components add to zero.

18. anonymous

im am still not sure

19. anonymous

d|dw:1328417056124:dw| You have these three vectors to worry about. Adding the x components gives you zero even if you include the weight vector because as you can see in the picture weight has a x-component of zero.

20. anonymous

they add to zero because there is no movement.

21. anonymous

there is also no movement in the y direction but weight has a -y component.

22. anonymous

even if they have different angles, like cos43 and cos 38

23. anonymous

those indicate the direction of the vectors. Multiplying them by the magnitude will give you your components.

24. anonymous

Notice how I put magf1<-x,y> for vector f1. That vector has a negative x component.

25. anonymous

So in my example, based on how you did it, my magnitude for f1 would be given by:|dw:1328417583344:dw|

26. anonymous

?

27. anonymous

Did you say you have the answers to this problem?

28. anonymous

but yes that should be the magnitude of f1 by algebraic methods

29. anonymous

its like 148.55...something

30. anonymous

for the weight right?

31. anonymous

yes for the weight

32. anonymous

okay yeah you should be getting 118.52.. for f1

33. anonymous

more importantly do you understand?

34. anonymous

yes i do thank you very much