Vector Calculations | Find ⎮v-2w⎮

In summary, a vector calculation involves manipulating quantities with both magnitude and direction. The formula for finding the magnitude of a vector is √(x^2 + y^2 + z^2). The Pythagorean theorem can also be used to find the magnitude of a vector. Vectors differ from scalars in that they have both magnitude and direction, while scalars only have magnitude. The difference of two vectors can be found by subtracting the components of the second vector from the first vector. This can also be represented as the magnitude of the difference vector being equal to the square root of the sum of the squared differences of each component.
  • #1
MozAngeles
101
0

Homework Statement



If ⎮v⎮=2, ⎮w⎮=3, and the angle between v and w is [tex]\pi/3[\tex], find ⎮v-2w⎮.

Homework Equations



Im not sure how to go about this. maybe use [tex]\cos\theta[\tex]=u∙v/⎮u⎮⎮v⎮

The Attempt at a Solution


i'm not sure where to start. i know this has to be pretty straightforward, but i don't see it...
anyt help would be nice thanks.
 
Physics news on Phys.org
  • #2
Hi MozAngeles! :smile:

(write /tex not \tex :wink:)

hint: |v - 2w|2 = (v - 2w).(v - 2w) :wink:
 

1. What is a vector calculation?

A vector calculation is a mathematical operation that involves manipulating vectors, which are quantities that have both magnitude and direction.

2. What is the formula for finding the magnitude of a vector?

The formula for finding the magnitude of a vector is √(x^2 + y^2 + z^2), where x, y, and z are the components of the vector in three-dimensional space.

3. How do you find the magnitude of a vector using the Pythagorean theorem?

To find the magnitude of a vector using the Pythagorean theorem, you square each component of the vector, sum the squares, and then take the square root of the sum. For example, if a vector has components (3,4,5), the magnitude would be √(3^2 + 4^2 + 5^2) = √(9 + 16 + 25) = √50 = 7.07.

4. What is the difference between vectors and scalars?

Vectors have both magnitude and direction, while scalars only have magnitude. For example, velocity is a vector quantity because it has both magnitude (speed) and direction, while speed is a scalar quantity because it only has magnitude.

5. How do you find the difference of two vectors?

To find the difference of two vectors, you subtract the components of the second vector from the components of the first vector. For example, if v = (2,3) and w = (1,4), then v-w = (2-1, 3-4) = (1,-1). This can also be represented as v-w = (1,-1) or ⎮v-w⎮ = √(1^2 + (-1)^2) = √2.

Similar threads

  • Calculus and Beyond Homework Help
Replies
2
Views
1K
  • Calculus and Beyond Homework Help
Replies
2
Views
2K
  • Calculus and Beyond Homework Help
Replies
1
Views
1K
  • Calculus and Beyond Homework Help
Replies
5
Views
2K
  • Calculus and Beyond Homework Help
Replies
1
Views
1K
  • Calculus and Beyond Homework Help
Replies
5
Views
1K
  • Calculus and Beyond Homework Help
Replies
1
Views
770
  • Calculus and Beyond Homework Help
Replies
1
Views
666
  • Calculus and Beyond Homework Help
Replies
8
Views
1K
  • Calculus and Beyond Homework Help
Replies
8
Views
1K
Back
Top