Electric forces and Electric fields question on x and y components

AI Thread Summary
The discussion centers on confusion regarding the classification of components in a physics problem involving electric forces and fields. The original poster questions why T cos theta and mg are labeled as x components when they appear to be on the y-axis. Participants clarify that the designation of components depends on the orientation of the coordinate system used in the problem. Misunderstandings often arise from rigid interpretations of trigonometric functions, where cosine is associated with horizontal (x) and sine with vertical (y) components. Emphasis is placed on understanding the geometry of the problem and the correct application of trigonometric definitions to resolve such confusion.
mattmro
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Homework Statement



please see the pictures!

Homework Equations



F=k(q1)(q2)/r^2



The Attempt at a Solution



okay, I am just curious as to why t cos theta and mg are x components when they are clearly on the y axix!
I thought you used cos for x components and sin for y components
 

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guys I know I am a DA, i barely got by in physics I and I was able to get by without knowing how to do these type of problems, now I can't please help!
 
The cosine of theta is the adjacent side of the triangle divided by the hypotenuse. With theta defined to be where it is in this problem, T cos theta is the vertical component of the tension.
 
mattmro said:
okay, I am just curious as to why t cos theta and mg are x components when they are clearly on the y axix!
I thought you used cos for x components and sin for y components
Where is it written that they are on X axis ... looks on Y to me
Maybe they took X as Y and Y as X

mikelepore said:
The cosine of theta is the adjacent side of the triangle divided by the hypotenuse. With theta defined to be where it is in this problem, T cos theta is the vertical component of the tension.
OP's asking why the vertical component is called X component
read question again
 
cupid.callin said:
OP's asking why the vertical component is called X component
read question again

I already read the question and the images about ten times before answering. It sounds to me like a teacher may have pounded it into the student's head that x means horizontal and then always take the cos, y means vertical and then always take the sin. I have heard some teachers say that, although it is wrong. The cure for the confusion is to identify the triangle and remember the "sohcahtoa" definitions of sin and cos.
 

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