Question

What type of vector multiplication is equivalent to finding the cosine of the angle between two vectors?

Answer 1

Do you know types of vector multiplication ?

Answer 2

Like, cross product and dot product?

Answer 3

Yes

Answer 4

Which vector multiplication involves cosine ?

Answer 5

Ohh, dot product. That makes sense.

We just took a test on kinematics, and part (a) of a question said to find the cross product between two vectors. I got that right but did not know part (b) which was "Verify that the cross product is perpendicular to both A and B." This question I asked was part of our test corrections.

Answer 6

Actually, even though I now know I have to use dot product, I'm still lost. How would I verify that it is perpendicular?

Answer 7

Two vectors are perpendicular if their dot product is zero as \( \cos 90 = 0\). You take two vectors A

Answer 8

and B and construct a vector as \(C = A \times B\)

Answer 9

Now check if A.C = 0 or B.C = 0

Answer 10

Got it! They both equal zero. Thanks so much.

Answer 11

I have one more question that was actually omitted from the test because so many people got it wrong....think you could help?

Answer 12

Go ahead

Answer 13

Would you like me to post it as a new question?

Answer 14

As you wish.. I am more interested in helping you

Answer 15

If you are posting it as a new question, then tag me

Answer 16

Oh I can do that? I just posted it.