Vectors (this is homeowrk)

[Jinn]

So my teacher enjoys throwing trick questions at us... and I think I'm looking at this one to hard and missing something simple... If anyone could help, not solve... that would be great

Problem reads, Find the Unit vector that has the same direction as the vector: v = 4j

multi choice
a) 2j
b) -j
c) j
d) i

im assuming v = 4j is a line going straight up? considering i = horizontal and j = vertical... with v = 4j, i is 0? so yeah... line going up 4 points? if you graph it

so I tried graphing the others 2j going up 2 points -j going down 1 point? j going up 1 i going right 1? I don't know >_<

a and c both seem like legit answers and that's where I'm confusing myself.

Thanks for the help in advance, I'll be watching this topic so I can learn to do this rather then cheat and just ask for the answer :/

[Orden]

The answer is 42.

[Jinn]

@_ @

[Deadgye]

A and C are both correct, your teacher needs to learn that multiple choice doesn't mean you put two or more correct answers in the same question.

[Jinn]

hmm, so I was graphing them correctly by going + or - whatever amount of points? while assuming that i or j was 0?

[Deadgye]

If we assign arbitrary directions to everything, j is the direction of j, and -j is the opposite direction. This means that 2j and j both point in the same direction as 4j. We don't even need to worry about i.

Vector notation is usually i,j,k though. So if you want you could probably think of i and j as x and y.

[Jinn]

aha, yes that what I was trying to say before in my backwards ass way of trying to explain how I was graphing.

Thanks for the help :D

[Blubbartron]

There are not two correct answers. The question specifically asks for UNIT vector. A unit vector has a magnitude of 1. Only one of those answers has both a magnitude of 1 and points in the same direction as the given vector.

[Kaelan?]

There are not two correct answers. The question specifically asks for UNIT vector. A unit vector has a magnitude of 1. Only one of those answers has both a magnitude of 1 and points in the same direction as the given vector.

This. A isn't normalized.

[Deadgye]

The question specifically asks for UNIT vector.

Wewps, didn't notice that lol.

[Jinn]

So then trying to graph them out wouldn't be the easiest way to finding the solutions to these? In this case it would since its a straight line but if the question was different could you take the v = 4j and divide it by the distance formula? to find its magnitude.

so you'd get something like (4j) / √(0)^2 + (4)^2 which = 4j/4 = j?

would that be a good way to find the answer?

[willriker]

A Unit Vecto9r has a magnitude of 1. there are not multiple answers here, there is only one correct answer. the answer is j.

[Silviya]

Yea, as stated answer c.) j is the correct answer. Answer a.) 2j is a vector in the same direction as 4j and j, but since the question specifically asked for a unit vector the only correct answer is c.) j.

[Ishido]

Really, no one caught

homeowrk

yet?

Slipping BG, slipping.

[Jinn]

Really, no one caught

yet?

Slipping BG, slipping.

it was a trick >_> if everyone saw homework then nobody would have came in here to help :/

[BarthelloSylph]

A and C are both correct, your teacher needs to learn that multiple choice doesn't mean you put two or more correct answers in the same question.

Unit vector means the only correct answer is j

[BarthelloSylph]

sounds like i was about the 8th person to say that

[Purrrfect]

So then trying to graph them out wouldn't be the easiest way to finding the solutions to these? In this case it would since its a straight line but if the question was different could you take the v = 4j and divide it by the distance formula? to find its magnitude.

so you'd get something like (4j) / √(0)^2 + (4)^2 which = 4j/4 = j?

would that be a good way to find the answer?

I think the easiest way to find the answer is just to look at the original vector and note it only has one of the 3 components. 4j tells you it is there are no angles because all of its magnitude is in one direction (j), and the unit vector is always one magnitude as others said.