## marsxtc 2 years ago Need help on Vectors ( Resultant, magnitude direction , was not here for lesson)

1. Leiaza

I would probably contact your teacher or a fellow student for help

2. marsxtc

|dw:1362001343487:dw|

3. marsxtc

I dont understand the question, it asks for me to use a graphing utility to graph it and find the resultant , and magnitude / direction?

4. Leiaza

there is a free graphing program online that is pretty helpful what does the actual problem say

5. marsxtc

says that ^

6. amistre64

the resultant is vector is simliar to an average of the 2 vectors|dw:1362001906941:dw|

7. marsxtc

I know its similar, but I'm more of it being xi+xj, at this point I don't understand

8. Leiaza

don't you multiply all 3 numbers it's been awhile since I've done this kind of stuff

9. amistre64

the ij parts are notations that are rather pointless in my opinion. the just stand for the xy compnent parts

10. amistre64

the magnitude can be found using law of cosines, but youll have to add 180 one of the vectors to use it

11. amistre64

is that 82 and 12 degrees? with 12 and 8 magnitudes?

12. marsxtc

Its 82 and 12 degrees, and the magnitude of the above is 12 and the below is 8

13. amistre64

|dw:1362002125432:dw|

14. amistre64

the component parts of the individual vectors uses sin and cos of their angles times their length <12cos(82),12sin(82)> and <8cos(360-12),8sin(360-12)>

15. amistre64

you can subtract the components parts to get the resultant components

16. marsxtc

To find direction isn't the equation tan-1)= b/a?

17. amistre64

it can be i spose. that would be the inverse tangent of the resultant vector components

18. amistre64

say your vectors are something more readable like: <3,4> and <1,1> the resultant is just the subtraction of one from the other <3,4> - <1,1> ------- <2,3> the direction is then that tan^-1 (3/2)

19. amistre64

or am i confusing things again?

20. amistre64

|dw:1362002809662:dw|

21. amistre64

ok, resultant is a+b, not a-b :)