Unit Vector Notation (part 2)

More on unit vector notation. Showing that adding the x and y components of two vectors is equivalent to adding the vectors visually using the head-to-tail method

Category:

Education

Tags:

• adding
• vectors
• physics
• calculus

[ReaverKS]

It wasn't confusing, you did a very good job of explaining, 5 out of 5

[madscirat]

School - grading curves - standardized testing - uninterested students -uninspired teachers = learning. Thanks Sal.

[sameenn]

u should be awarded noble prize!!!

[ppenna]

@ladymarmalade1710 The unit vectors are positive to start.  Example: i = 1 in the x direction unit, j=1 in the y direction. So by definition yes it is positive, but when you multiply i by a negative number it goes the opposite direction of i. Just like when you multiply any positive number by a negative number. -4i is just saying the vector's direction and magnitude on the x axis is going to the point (-4, 0).

[ladymarmalade1710]

I have a question regarding unit vectors. My teacher told me that unit vectors only represent the positive direction of an axis. If this is true, then why can we draw -3i in the negative direction? How does -3i even exist if the unit vector only applies to the positive direction of the axis? Any help would be appreciated. Thanks!

[SpasticWire]

thanks (i got it already though)

[dlwodnd]

@SpasticWire because its been 2 months so i dont know if you are still interested in the answer

but you use the trigonometry to figure out the direction.

For instance, from the example in the video, when the vectors of the resultant was -1i + 6j

the "opposite" side is 6 and "adjacent" side is 1

using inverse tangent, the angle is 80.5 degrees from the negative x-axis

hope this helped if you havent figured this out already :)

[SpasticWire]

How do you get the direction of the resultant vector using the unit vector notation??

[superbigpony]

hairy balls

[123456sag]

all good words in dictionery

[lawrencewong100]

now i can pass my quiz tomorrow without payin attention in class~ hahaha xDD