What Happens to the Magnitude of a Vector When Rotated?

[debabo007]

hi everyone, i was doing my physics homework and i had problems in these 2 MC quesitons.

#1 A vector originally at a direction of 30°, when measured counter-clockwise with respect to the +x axis, is rotated a further 30° counter-clockwise.
The magnitude of the vector will ...

a.Increase by a factor of four
b.Increase by a factor of two
c.Remain the same
d.Decrease by a factor of two
e.Decrease by a factor of four

#2 The components of vector are Ex = +150 N/C and Ey = -100 N/C.
If we measure all angles with respect to the +x axis and counter-clockwise as the positive direction, the direction of is closest to:


a. -326°
b. -56°
c. -34°
d. +34°
e. +304°

 

[flyingpig]

1) What do you think?

2) Draw the components.

 

[ex81]

1) draw a 30 degree, and 60 degree angle. but think about this: does your magnitude have anything to do with the changing of angles?