What Is the Final Position of a Vector Rotated Clockwise by 110°?

[Torshi]

Homework Statement

Vector A is initially pointing eastward. This vector is rotated clockwise by an angle of 110°. Which of the following statements is correct regarding the final position of vector A ?

Homework Equations

none

The Attempt at a Solution

I narrowed down my choices to 2:

Vector A is initially pointing eastward. This vector is rotated clockwise by an angle of 110°. Which of the following statements is correct regarding the final position of vector A ?

It is pointing 70° east of south.
or
It is pointing 70° south of east.
What's the difference?

The vector ends up in 4th quadrant with a 70 degree angle but i can choose which choice it is.

 

[Torshi]

nvm i understand:

Answer equals 20 degrees west of south

 

[Doc Al]

It is pointing 70° east of south.
or
It is pointing 70° south of east.
What's the difference?

For 'east of south' you start off pointing south, then go east. Which way is east?
For 'south of east' you start off pointing east, then go south.

Compare these directions with the given vector. (Actually draw a diagram, indicate east, then rotate by 110 degrees.)

The vector ends up in 4th quadrant with a 70 degree angle but i can choose which choice it is.

You might want to reconsider the other choices.

 

[Doc Al]

Answer equals 20 degrees west of south

There you go.

 

[rwisz]

As a scientist, the correct statement would be "It is pointing 70° south of east." This is because in mathematics and physics, angles are typically measured counterclockwise from the positive x-axis. In this case, the initial position of vector A is eastward, which is 0°. Rotating it clockwise by 110° would result in a final position of 110° south of east, or 70° clockwise from the positive x-axis.