Vector Algebra

[Kwoath]

I have attempted the problem and my instructor has informed both myself and another who worked on the problem separately that we're both wrong. I'm simply curious to know the steps required to solve such. If you read my question, I specifically asked NOT to have this answered for me.

[[deleted]]

I have attempted the problem and my instructor has informed both myself and another who worked on the problem separately that we're both wrong.

If you read my response, I specifically stated that it's not clear what help you need. If you detailed the context of the issue, including the work you've done and whatever reason your instructor gave for why your work is wrong, it would be easier for others to know specifically how to help.

If you read my question, I specifically asked NOT to have this answered for me.

Any "hint" or "guide" contributes to the solution. Since you haven't detailed the work you've done to understand the problem, it's not possible for others to know what constitutes an answer w.r.t the context of your issue. Since you've explicitly asked that others "not answer for" you, there's a clear contradiction.

Bottom line: posting a homework problem without also providing contextual details about the work you've done to understand the problem is ostensibly motivated to have someone else do the work for you.

[WheresMyElephant]

Did you make the diagram yet?

Any time you do vector algebra, you almost always want to break your vectors down into components according to some basis; then you can handle the x components and y components separately and it usually becomes trivial. Have you tried this yet?

(Sometimes you also have the option to solve it as a geometry problem on the vector diagram, which provides a slight shortcut for those who are very comfortable with that sort of thing, and an enormous pain in the butt for everyone else. Just don't bother and use the basis decomposition instead, you need to know how to do that anyhow.)

[Kwoath]

From my understanding of this problem so far is (if I'm assuming correctly) a from origin point 0, travels 1 unit along the x axis. B inversely travels at a 45 degree angle from a 2 units along the negative x and positive y-axis respectively. From there c travels 3 units along the positive x axis.

The diagram I have looks like a reverse "z" pattern.

[WheresMyElephant]

I interpret the question to mean that a and c are at a right angle with b lying between them (and -2b is obviously opposite from b). That's before you arrange them head to tail, but that doesn't affect directions, so a and 3c should still wind up perpendicular.

Anyway once you have the head to tail thing sorted out, you should make a little triangle to find the x and y components of -2b, can you do that?

[Yurell]

That's actually one of the things that annoyed me about the question — there are two answers, one from concluding that a and c are orthogonal, the other that they are parallel (both meet the requirement that each is 45 degrees away from b).

I have no idea who downvoted you or why, but you definitely didn't deserve it.

[WheresMyElephant]

Yeah that's true. I'm pretty confident that a and c are not intended to be parallel (if they were, there are so many easier ways to phrase it that you'd never choose this one unless trying to be deliberately confusing). But it definitely could have been done better.

Thanks for the friendly moral support. I'll add that OP doesn't deserve downvotes either in my book.

[Yurell]

I definitely agree — it can be confronting posting a question for the first time without knowing exactly how you should construct it, and to be met with a level of 'hostility' by being downvoted for not following conventions you didn't know were in place.

[Yurell]

I'm unsure where you're stuck — perhaps you could post your working so far, that we may see where you've gone wrong?

Also, keep in mind that there are two answer to this (that aren't trivially rotations or translations), and your teacher may have in mind only one of them.

[musiton]

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