Lesson Plan on Vector Addition

Lesson Plan on Vector Addition

Objectives: Students will be able to

  1. identify vector quantities.
  2. represent vectors with symbols.
  3. add vectors to find the resultant.
  4. use parallelogram method, consecutive method, and method of components to find the sum of vectors.

Grade Levels: 10 -12

Background Information:

Vectors are quantities that describe direction and magnitude. An arrow is the symbol used to represent a vector. The length of the arrow describes the magnitude of the vector while the direction the arrow is pointing indicates the direction the object is moving. For example, a velocity like 30 km/hr East is a vector because it means how fast something is moving and in what direction.

[Arrow]

If two vectors act on an object, the sum of the vectors, or resultant vector, can be calculated.

[Example with canoe vs. current]

If two vectors are moving the same direction or opposite directions the resultant vector can be calculated by simple addition or subtraction, as shown above. However, the resultant becomes more complicated to calculate if this is not the case. Other methods, shown below, can be used to calculate the resultant vector. With precise drawings with a ruler and protractor, the resultant can be measured with a ruler.

[Graphical Methods of Vector Addition]

These graphical methods adequately illustrate concepts (see Aspects of Launching a Spacecraft) but may not be very accurate numerically and would be better suited for a good estimation of the resultant. The method of components is more accurate, and often more convenient, because the resultant can be calculated using right triangle methods. The graphs do not have to be precisely drawn.

[Components Method of Vector Addition]

Use of other trigonometry functions can reduce a resultant to its component parts. In the following example, the components of the two vectors are found first, and then the results are used to find the resultant vector.

[Tugboats pulling a ship example]

Activities:

Activity: Worksheet on Vector Addition

No Frames Table of Contents

[LMGFP home page] Contact Karen Krupinsky (kgurley@gsfc.nasa.gov) or
Tammy Seergae (tseergae@umd.edu) for further information.