OML Search

Vector Addition




 
In these videos and solutions, we will learn
  • how to add vectors geometrically using the ‘nose-to-tail’ method or "head-to-tail" method or triangle method
  • how to add vectors using the parallelogram method
  • that vector addition is commutative
  • that vector addition is associative
  • how to add vectors using components

Related Topics: More lessons on Vectors

"Nose-to-Tail" Method

Vectors can be added using the ‘nose-to-tail’ method or "head-to-tail" method.

Two vectors a and b represented by the line segments can be added by joining the ‘tail’ of vector b to the ‘nose’ of vector a. Alternatively, the ‘tail’ of vector a can be joined to the ‘nose’ of vector b.


Example:

Find the sum of the two given vectors a and b.


Solution:

Draw the vector a. Draw the ‘tail’ of vector b joined to the ‘nose’ of vector a. The vector a + b is from the ‘tail’ of a to the ‘nose’ of b.




Example:

Given that , find the sum of the vectors.

Solution:



Triangle Law of Vector Addition

In vector addition, the intermediate letters must be the same. Since PQR forms a triangle, the rule is also called the triangle law of vector addition.



Graphically we add vectors with a "head to tail" approach.



 
The addition of vectors using the head-to-tail method.
Parallelogram Law of Vector Addition
Vectors can be added using the parallelogram rule or parallelogram law or parallelogram method.
Graphical Method of Vector Addition (Parallelogram Method).


How to add and subtract vectors at any angle.
Includes parallelogram method and worked examples.
How to add vectors by scale drawing?
1. Choose a scale
2. Draw the vectors so the tip of one vector is connected to the tail of the next
3. Make sure the length and direction of each arrow is correct.

How to add vectors by the parallelogram method?
The resultant is the diagonal starting from the joined tails.

When adding two vectors, the biggest resultant possible is when the vectors are parallel.
This video shows two methods used to add vectors graphically: "Tail-to-tip" method and parallelogram method.


 
Vector Addition is Commutative

We will find that vector addition is commutative, that is a + b = b + a

This can be illustrated in the following diagram.


Vector Addition is Associative

We also find that vector addition is associative, that is (u + v) + w = u + (v + w ).

This can be illustrated in the following two diagrams. Notice that (u + v) + w and u + (v + w ) have the same magnitude and direction and so they are equal.


Example:

ABCD is a quadrilateral. Simplify the following:



Add Vectors using components
Vectors are added by adding the corresponding components.

How to Add vectors using components (part 1)
An example of how to add two vectors by using their components. This video goes through breaking them down, and adding the components.
How to Add vectors using components (part 2)


 
Vector Word Problems
The following video shows how of vector addition can be used to solve word problems.
Example 1: A plane is flying west at 600 km/hr with a wind blowing from the north at 200 km/hr. Find the true direction of the plane.
Relative Motion Vector Addition: physics challenge problem
This video demonstrates a relative motion problems that is solved using vector addition.
Example: A tour boat has two hours to take passengers from the start to finish of a tour route. The final position is located 18.6 km from the start at 26 degrees north of west. There is a current in the water moving at 6.4 km/hr with a global angle of 255 degrees. What would be the boat's velocity (magnitude and direction) relative to the body of water to reach the destination at the correct time?

Rotate to landscape screen format on a mobile phone or small tablet to use the Mathway widget, a free math problem solver that answers your questions with step-by-step explanations.


You can use the free Mathway calculator and problem solver below to practice Algebra or other math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations.


OML Search


We welcome your feedback, comments and questions about this site or page. Please submit your feedback or enquiries via our Feedback page.


[?] Subscribe To This Site

XML RSS
follow us in feedly
Add to My Yahoo!
Add to My MSN
Subscribe with Bloglines