Physics vector help pls?

suppose that u have three vectors. A=3i+4j, B=2i-2j+4k, and C= -i+5j - 3k. show that the sum of these three vectors can alternatively be computed by first summing vector A and B and then summing the resultant with vector C or by first summing vector B and C and then summing the resultant with vector A.

Physics vector help pls?
A + B = (3+2)i +(4-2)j + (0+4)k


= 5i + 2j + 4k





A+B+C = (5-1)i +(2+5)j + (4-3)k


= 4i + 7j +1k
Reply:I hope you know what vectors actually are?? If not, you'd better start from the beginning, and this time READ through the text, don't just look at the examples!


Say your vector A=3i+4j.. Technically, it is a point in a cartesian frame which is 3 units on the x-axis and 4 units on the y-axis (and zero on the z-axis, but forget that for now), measured from the origin, i.e., the point of concurrence of the three mutually perpendicular axes. So just imagine an arrow pointing in a direction like that, the way you've done graphs in lower classes. Now when you're adding two vectors, what you get is a resultant vector, hence it should have magnitude and direction. In this case, it's pretty easy, since you have the COMPONENTS of each vector along the reference axes, so you can directly add them, without having to worry about "vector addition". Just read the book a bit, you'll get it.
Reply:In order to find the resultant vector of A and B just add the two vectors. Standard dimension wise addition of vectors. Then add C in the same manner to the result of A and B.


For B and C, just add them to find their resultant and then add A. The result will be the same.
Reply:Since you already have the COMPONENTS of the three vectors (i.e., the i, j, and k components), it is easy to see that you can add together the i's, j's, and k's for A and B, and then add those for C,


-O R-


you add together the i's, j's, and k's for B and C, and then add those for A.
Reply:http://www.upscale.utoronto.ca/GeneralIn...


This should help. I learned vectors first graphically, so that might help you move into a numerical way of dealing with vectors, but this is hard because its a new type of math, unlike the scalar math that they teach in everyother math.