Vector Direction - Questions 9 Help

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Vector quantities are quantities like displacement and force (to name just two) that are fully described by expressing a magnitude (or numerical value) and a direction. Agreed-upon conventions are required to express the direction of any vector that is not aligned with the traditional east-west-north-south compass directions. One convention involves identifying the angle and direction of rotation that the vector makes with one of the two nearby axes (or compass directions).

There are three similar versions of this question. Each includes a vector located in the third quadrant. The task involves determining the direction of the vector as expressed as an angle of rotation from one of the two nearby axes or compass directions.

Questions 25-27:

Use the protractor to determine the direction of the given vector. Express your answer as an angle of rotation some direction from one of the two nearest axes. (The angle measure is a multiple of 15 degrees.)

The convention used in this question involves expressing the direction of the vector as an angle of rotation from one of the nearby axes. This vector lies between South and West. You might describe it as being rotated westward from South. Or you could decribe it as being rotated southward from West. Either way, you will need to measure the angle the vector makes with South or West. Then describe the direction you have measured from. If you measured the angle the vector makes with South, then you have measured the angle West of South. On the other hand, if you measured the angle the vector makes with West, then you have measured the South of West.

The protractor can be dragged on top of the vector so that the origin of the protractor lies at the tail of the vector; that's the dot ... not the arrowhead. Bold markings are shown every 15°. This allows you to measure the angle of rotation. Complete this task and then enter the angle into the answer field. Finally, tap (or click) on the box with the "--" symbol to identify the angle as being measured either South of West or West of South.

Try this link to The Physics Classroom Tutorial for more help with vector direction:

Vector Direction