Skip to main content
Physics

You are not logged in. Your edit will be placed in a queue until it is peer reviewed.

We welcome edits that make the post easier to understand and more valuable for readers. Because community members review edits, please try to make the post substantially better than how you found it, for example, by fixing grammar or adding additional resources and hyperlinks.

3
  • 1
    $\begingroup$ It is that dx. The dm is almost the hypothenuse, dy is then the vertical third leg of that triangle. tangent is a slope, by definition of tangent. Thus, there is an angle (very close to the vert opp angle of $\theta_1$) where it is the tangent of $\endgroup$
    – naturallyInconsistent
    Commented Apr 20, 2023 at 5:23
  • 2
    $\begingroup$ How is this homework? It's question about a derivation for equation of motion of a string. The close voters (and you know who you are) need to examine their views about helping other people understand physics as well as they do. $\endgroup$
    – John Rennie
    Commented Apr 20, 2023 at 7:59
  • $\begingroup$ In my experience the slope $dy/dx$ is usually denoted $\tan\psi$ to avoid conflation of $\psi$ with the polar angle $\theta$. $\endgroup$
    – J.G.
    Commented Apr 20, 2023 at 8:22