What is the scalar product V_1(DOT)V_2 ?

In summary, the conversation discusses finding the components and magnitude of two vectors, V_1 and V_2. V_1 has a magnitude of 80 and points along the z-axis, while V_2 lies in the xz plane, has a magnitude of 51, and makes a -49 degree angle with the x-axis. The equations A.B=ABCos(theta) and Cos(theta)=(AxBx+AyBy+AzBz)/AB are used to find the x, y, and z components of each vector. The final answer for V_2 is -3079.2.
  • #1
Rellsun
3
0

Homework Statement



Vector V_1 points along the z axis and has magnitude V_1 = 80. Vector V_2 lies in the xz plane, has magnitude V_2 = 51, and makes a -49o angle with the x-axis (points below x axis)

Homework Equations



A.B=ABCos(theta)=AxBx+AyBy+AzBz

Cos(theta)=(AxBx+AyBy+AzBz)/AB

The Attempt at a Solution



im not really sure where to go from here I am not sure if those equations are useful
 
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  • #2
The equations are indeed useful. Find the x,y and z components of each vector, then apply the first equation that you posted.
 
  • #3
ok that helps a lot i don't know why i did do that. but how do you find the z component of the V_2=51?
 
Last edited:
  • #4
Rellsun said:
Vector V_2 lies in the xz plane, has magnitude V_2 = 51, and makes a -49o angle with the x-axis (points below x axis)

Draw yourself two axes in the plane of the paper. Label the horizontal one x and the vertical one z (instead of the usual y). Draw the vector as indicated. Can you find its x and z components?
 
  • #5
ahh thanks that makes much more sense. i got the final answer to be -3079.2 which is indeed correct. the help is appreciated.
 

Related to What is the scalar product V_1(DOT)V_2 ?

1. What is the scalar product V_1(DOT)V_2?

The scalar product, also known as the dot product, is a mathematical operation that takes two vectors as input and produces a scalar value as output. It is denoted by a dot (·) or sometimes by parentheses, as in V_1(DOT)V_2.

2. How is the scalar product calculated?

The scalar product of two vectors, V_1 and V_2, is calculated by multiplying the magnitudes of the two vectors and then multiplying the cosine of the angle between them. This can be represented by the formula V_1(DOT)V_2 = |V_1| * |V_2| * cosθ.

3. What is the purpose of the scalar product in physics and mathematics?

The scalar product has various applications in physics and mathematics. In physics, it is used to calculate the work done by a force on an object, as well as determining the angle between two vectors. In mathematics, it is used to find the angle between two vectors, project a vector onto another vector, and determine the length of a vector.

4. How is the scalar product related to the vector product?

The scalar product and the vector product are two different operations involving vectors. The scalar product produces a scalar value, while the vector product produces a vector. However, the two operations are related through the triple product formula, which states that the scalar product of two vectors, V_1 and V_2, multiplied by the sine of the angle between them, is equal to the magnitude of the cross product of the two vectors.

5. What are some real-life examples of the scalar product?

The scalar product has various real-life applications. For example, in physics, it is used to calculate the work done by a force on an object, as well as determining the angle between two vectors. In engineering, it is used to calculate the moment of a force and determine the angle of a force relative to a given axis. In architecture, it is used to calculate the angle between two walls of a building.

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