Skip to main content
Pearson+ LogoPearson+ Logo
Ch 01: Units, Physical Quantities & Vectors
Young & Freedman Calc - University Physics 14th Edition
Young & Freedman Calc14th EditionUniversity PhysicsISBN: 9780321973610Not the one you use?Change textbook
Chapter 1, Problem 42a

Find the scalar product of the vectors A and B given in Exercise 1.38.

Verified step by step guidance
1
First, recall the definition of the scalar product (also known as the dot product) of two vectors. The scalar product of vectors \( \mathbf{A} \) and \( \mathbf{B} \) is given by \( \mathbf{A} \cdot \mathbf{B} = A_x B_x + A_y B_y + A_z B_z \), where \( A_x, A_y, A_z \) are the components of vector \( \mathbf{A} \) and \( B_x, B_y, B_z \) are the components of vector \( \mathbf{B} \).
Identify the components of vectors \( \mathbf{A} \) and \( \mathbf{B} \) from Exercise 1.38. Let's assume \( \mathbf{A} = (A_x, A_y, A_z) \) and \( \mathbf{B} = (B_x, B_y, B_z) \).
Substitute the components of vectors \( \mathbf{A} \) and \( \mathbf{B} \) into the scalar product formula: \( \mathbf{A} \cdot \mathbf{B} = A_x B_x + A_y B_y + A_z B_z \).
Calculate each term of the sum separately: \( A_x B_x \), \( A_y B_y \), and \( A_z B_z \).
Add the results of the individual products to find the scalar product: \( \mathbf{A} \cdot \mathbf{B} = A_x B_x + A_y B_y + A_z B_z \). This sum gives the scalar product of the vectors.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
1m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Scalar Product

The scalar product, also known as the dot product, is a mathematical operation that takes two vectors and returns a single number. It is calculated by multiplying the magnitudes of the vectors and the cosine of the angle between them. This operation is useful for determining the angle between vectors or projecting one vector onto another.
Recommended video:
Guided course
09:07
Introduction to Dot Product (Scalar Product)

Vector Magnitude

Vector magnitude refers to the length or size of a vector, which is calculated using the square root of the sum of the squares of its components. Understanding vector magnitude is crucial for computing the scalar product, as it is one of the factors multiplied in the dot product formula.
Recommended video:
Guided course
03:59
Calculating Magnitude & Components of a Vector

Angle Between Vectors

The angle between vectors is a measure of how much one vector is rotated relative to another. It is essential for calculating the scalar product, as the cosine of this angle is used in the dot product formula. Knowing the angle helps in understanding the directional relationship between vectors.
Recommended video:
Guided course
05:56
Calculating the Angle Between 2 Vectors Using the Dot Product