# Homework Help: Vector rotation, basic.

1. Jul 16, 2011

### Torshi

1. The problem statement, all variables and given/known data

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 ?

2. Relevant equations

none

3. 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.

2. Jul 16, 2011

### Torshi

nvm i understand:

Answer equals 20 degrees west of south

3. Jul 16, 2011

### Staff: Mentor

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.)

You might want to reconsider the other choices.

4. Jul 16, 2011

### Staff: Mentor

There you go.