- #1

- 367

- 2

## Homework Statement

So this isn't really a specific homework question, it's more of a general one. What is the difference between a

_{x}and i(hat)? I thought they were the same thing. Can someone please explain the difference?

You are using an out of date browser. It may not display this or other websites correctly.

You should upgrade or use an alternative browser.

You should upgrade or use an alternative browser.

- Thread starter jdawg
- Start date

- #1

- 367

- 2

So this isn't really a specific homework question, it's more of a general one. What is the difference between a

- #2

Chestermiller

Mentor

- 21,155

- 4,671

By a_{x}, are you referring to a coordinate basis vector? Please provide more context.

- #3

- 367

- 2

Sorry, yes that's what I meant. Like the x component of a vector a.

- #4

Chestermiller

Mentor

- 21,155

- 4,671

It still isn't clear to me. Please provide a specific example or two.Sorry, yes that's what I meant. Like the x component of a vector a.

Chet

- #5

- 367

- 2

- #6

BvU

Science Advisor

Homework Helper

- 14,401

- 3,712

j(hat) idem in the y direction.

So if for example vector

the length of the x-component of

the length of the y-component of

Often, vectors are printed in bold, as I did with the

Because they are vectors too, I should also have used [itex]\bf\hat i[/itex] and [itex]\bf\hat j[/itex] or better, bold versions of [itex]\bf\hat \imath[/itex] and [itex]\bf\hat \jmath[/itex] without the dot, and perhaps upright but I can't find them....

- #7

- 367

- 2

- #8

SteamKing

Staff Emeritus

Science Advisor

Homework Helper

- 12,796

- 1,670

- #9

- 367

- 2

Ohhh so i, j, and k aren't actually on the axes?

- #10

SteamKing

Staff Emeritus

Science Advisor

Homework Helper

- 12,796

- 1,670

i = (1, 0, 0)

j = (0, 1, 0)

k = (0, 0, 1)

with the origin at (0, 0, 0)

These three vectors are mutually perpendicular to one another and are aligned and coincident with the three cartesian coordinate axes.

- #11

Chestermiller

Mentor

- 21,155

- 4,671

No. They are directions parallel to the axes. You express vectors as the sum of scalar components times the unit vectors so that you add and subtract the individual terms like vectors (so they automatically satisfy the parallelogram rule for adding and subtracting vectors). It makes it very convenient to handle them mathematically. In physics problems, you are often resolving vectors into their components perpendicular and tangent to surfaces. In such cases, the unit vectors perpendicular and tangent to the surfaces come in particularly handy, and they are often not parallel to the coordinate axes.Ohhh so i, j, and k aren't actually on the axes?

Chet

Share: