Vector Problem

[Hexon]

---

Members do not see this ad.

from a textbook:

You have 2 displacement vectors; A with a magnitude of 8.0m in a direction 45 degrees below the +x-axis, and B which has an X-component of _2.0m and a y-component of +4.0m.
Find Vector C so that A+B+C equals Vector D which has a magnitude of 6.0m in the +y-direction.

 

[MT Headed]

I don't mean to be a jerk about it, but this forum is for MCAT question Q+A, not homework Q+A. I seriously doubt you would find a problem like this on the MCAT.

That being said, two dimensional vector problems are best approached by thinking about the human world vs. the physics world. In the human world, people talk about vectors having a length and a direction (often measured in degrees).

Physicists are not human. They break up all human vectors into an alternate language, where each vector has an X part and a Y part such that the original human vector is the sum of these parts. The laws of physics apply individually in X world and in Y world, which are pretty simple worlds, and this will produce an answer also in X world and in Y world.

Now that you have a physicist answer in X world and Y world, often times you need to translate the physicist answer back into human terms to produce an answer that your boss or your neighbor or any normal human being can deal with.

Translating from human world to physicist world involves sines and cosines. Translating back from physicist world to human world involves arctangents and the pythagorean theorem.

Good luck.

 

[Hexon]

thanks i'd seen it in my college textbook and was pondering over it. Now that you've put it that way it makes a lot more sense now🙂