Thread: physics, displacement problem

The x component of a displacement vector is -2.7 cm, the displacement has a magnitude of 6.7 cm, and the y component is negative.

a. Need to find the angle of the vector, relative to the x-axis?
So have to give as an angle between -180° and +180°.
°
b. also, need to find the y-component of the displacement?
in cm:

Any help with this would be appreciated please.

Well since you know the x component and the magnitude you can set up an equation to find the angle like

$\displaystyle \bigtriangleup x=magnitude * cos(\theta)
$

then use the knowledge that the y component is negative to give the angle theta the correct sign. Next solve for y as you did for x.

$\displaystyle \bigtriangleup y=magnitude *sin(\theta)
$

And your done.