Finding the components of this velocity vector

[PleaseAnswerOnegai]

Homework Statement

A velocity vector has magnitude 100.0 m/s and make an angle of 160° with the positive x-axis. Determine the x- and y-components of the vector.

Relevant Equations

Trig functions

 

[berkeman]

Homework Statement:: A velocity vector has magnitude 100.0 m/s and make an angle of 160° with the positive x-axis. Determine the x- and y-components of the vector.
Relevant Equations:: Trig functions

View attachment 269386

Welcome to PhysicsForums.

That sketch looks wrong. What line is 180 degrees from the x-axis? So 160 degrees would be pretty close to that line, not vertical like that...

 

[PleaseAnswerOnegai]

Just started Physics and I wasn't sure if my answer and solution was right. I attempted to project it on the cartesian plane based on my understanding. It said "an angle of 160 with the positive x-axis." What I understood from this is that angles of the triangle that makes contact to the x-axis equal to 160 so I assumed the angles would be 70 and 90.

 

[PleaseAnswerOnegai]

Welcome to PhysicsForums.

That sketch looks wrong. What line is 180 degrees from the x-axis? So 160 degrees would be pretty close to that line, not vertical like that...

Hi! What would the correct sketch look like? While I was sketching it I knew something was fishy and I just had to ask hahaha

 

[berkeman]

Just started Physics and I wasn't sure if my answer and solution was right. I attempted to project it on the cartesian plane based on my understanding. It said "an angle of 160 with the positive x-axis." What I understood from this is that angles of the triangle that makes contact to the x-axis equal to 160 so I assumed the angles would be 70 and 90.

No, usually the angle is measured counterclockwise from the horizontal x-axis. So an angle of 90 degrees is straight up (along the y-axis), and an angle of 180 degrees is pointing left along the -x-axis. So where would 160 degrees counterclockwise from the x-axis be? And what would the x- and y- components of that vector be then?

 

[berkeman]

Like this:

http://mathsfirst.massey.ac.nz/Trig/DegRad.htm

 

[PleaseAnswerOnegai]

Like this:

http://mathsfirst.massey.ac.nz/Trig/DegRad.htm

View attachment 269388

So it would then be on the 2nd Quadrant, correct? What confused me was the usage of "positive x-axis" so I wrongfully assumed that it would be strictly in the 1st Quadrant (where x values are positive). I will solve it and send my answer! :)

 

[PleaseAnswerOnegai]

So it would then be on the 2nd Quadrant, correct? What confused me was the usage of "positive x-axis" so I wrongfully assumed that it would be strictly in the 1st Quadrant (where x values are positive). I will solve it and send my answer! :)

 

[PeroK]

Is the angle $20°$ or $160°$? Is the x-coordinate positive or negative?

 

[archaic]

View attachment 269390

It's true that $\sin(\pi-x)=\sin x$, but $\cos(\pi-x)=-\cos x$, not $\cos x$.