Does the Cross Product of -k and -i Result in +j?

In summary, the conversation discusses a simple cross product question and confirms that when multiplying two negative vectors, the result is a positive vector. The individual expresses gratitude for the quick response and mentions preparing for a final exam.
  • #1
max8404
11
0
simple cross product question. Please help!

Homework Statement



Hey guys, I know how cross product works,

i-->j-->k : positive numbers
i<--j<--k : negative number

Homework Equations



The question that I have is, say I have -k x -i, I am supposed to get a positive j since the two negatives cancel out, is that correct? I would really appreciate any help, I have a final in less than 10 hours and would love a quick response! :)
 
Physics news on Phys.org
  • #2


(-k)x(-i) is +j. Yes, it's the same as (k)x(i).
 
  • #3


Dick said:
(-k)x(-i) is +j. Yes, it's the same as (k)x(i).


excellent! thanks for your quick response. Now, to continue studying for this nasty final! :)
 

Related to Does the Cross Product of -k and -i Result in +j?

1. What is a simple cross product?

A simple cross product is a mathematical operation that takes two vectors as input and produces a third vector that is perpendicular to both of the input vectors. It is also known as a vector product or cross multiplication.

2. How is a simple cross product calculated?

The formula for calculating a simple cross product is:
a × b = (aybz - azby)i + (azbx - axbz)j + (axby - aybx)k
Where a and b are the input vectors, i, j, and k are unit vectors in the x, y, and z directions respectively, and the output is a new vector in the form of (x, y, z).

3. What is the physical significance of a simple cross product?

A simple cross product has many physical applications, such as calculating torque, determining the direction of magnetic fields, and finding the angular momentum of a rotating object. It is also used in 3D graphics and computer vision to calculate the orientation of objects.

4. Can a simple cross product be negative?

Yes, the value of a simple cross product can be negative. This indicates that the resulting vector is pointing in the opposite direction of the positive value. The negative value can also be interpreted as a change in direction or rotation.

5. Is a simple cross product commutative?

No, a simple cross product is not commutative. This means that the order in which the input vectors are multiplied affects the resulting vector. In other words, a × b does not equal b × a. This is because the direction of the resulting vector is dependent on the order of the input vectors.

Similar threads

Obtain an equation of the plane in the form ##px+qy+rz=d##
    • Calculus and Beyond Homework Help
Replies
5
Views
370
A Reason out the cross product (for the moment): a skew symmetric form
    • Linear and Abstract Algebra
Replies
14
Views
2K
What is the formula for the norm of a vector cross product?
    • Calculus and Beyond Homework Help
Replies
5
Views
1K
Calculating the time to cross a river
    • Introductory Physics Homework Help
Replies
4
Views
2K
B Confusion about the angle between two vectors in a cross product
    • General Math
Replies
7
Views
2K
Solution to the Two-Body Problem: Cross-Product and Dot-Product Integration
    • Introductory Physics Homework Help
Replies
2
Views
991
Effect of different magnetic fields on a magnetic dipole
    • Introductory Physics Homework Help
Replies
25
Views
356
Finding the Angle Between Vectors A and B in the Cross Product
    • Introductory Physics Homework Help
Replies
13
Views
2K
Where on a rigid body is a resultant force applied?
    • Introductory Physics Homework Help
Replies
11
Views
303
Finding dot product, cross, and angle between 2 vectors
    • Introductory Physics Homework Help
Replies
3
Views
1K

Hot Threads

Recent Insights

Back
Top