Timeline for How exactly are linear and rotational velocity and acceleration related?
Current License: CC BY-SA 4.0
23 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Apr 20, 2021 at 3:13 | answer | added | kbakshi314 | timeline score: 0 | |
| Apr 20, 2021 at 1:40 | history | edited | kbakshi314 | CC BY-SA 4.0 |
edited title
|
| Apr 20, 2021 at 1:08 | history | edited | kbakshi314 | CC BY-SA 4.0 |
grammatical edits and formatting changes and added tags
|
| Apr 19, 2021 at 22:42 | answer | added | DGAPhysics1 | timeline score: 0 | |
| Apr 18, 2021 at 14:27 | comment | added | garyp | You are correct about that. Your careful reading has run you right into the very common practice of not carefully distinguishing speed from velocity. Very often a textbook will define speed and velocity and then proceed to use them interchangeably. The book I'm teaching from right now does exactly that. You have to get used to discerning what is meant from context. | |
| Apr 18, 2021 at 14:15 | comment | added | agavemelon | @garyp If s is analog to displacement, for v = ωr, shouldn't v be named tangential velocity? Why does my textbook (and a lot of other sources) call it linear speed? That was originally the reason I had assumed s is analog to distance, and not displacement. | |
| Apr 18, 2021 at 14:05 | comment | added | garyp | Are you comparing motion along the arc of a circle and motion on a straight line chord between two points on a circle? If so you are really trying to describe what an apple tastes like by comparing it to the taste of an orange. Constrain your circular motion to a circle. Note that motion in a circle can be described using the rectilinear concepts, but the math is a lot more complicated than what you are trying to do. | |
| Apr 18, 2021 at 14:03 | comment | added | silverrahul | @mikeeei s shows the shortest length between two points ALONG the circle. Because, here your motion is along the circle, i.e. along the perimeter of the circle | |
| Apr 18, 2021 at 13:57 | history | edited | agavemelon | CC BY-SA 4.0 |
added 8 characters in body
|
| Apr 18, 2021 at 13:51 | answer | added | trula | timeline score: 1 | |
| Apr 18, 2021 at 13:44 | comment | added | agavemelon | @garyp If so, ds/dt must be a velocity because θ is analog to displacement, not distance. However, s, arc length, does not show the shortest length between two points on a circle. Therefore it cannot be a displacement. And now nothing makes sense... | |
| Apr 18, 2021 at 13:41 | comment | added | garyp | You need to define an analog of distance for rotations. Your $\theta$ is the analog of displacement, so it behaves like displacement. You don't have an analog of distance. You are using the variable $\theta$ to represent both angular distance and angular displacement. | |
| Apr 18, 2021 at 13:38 | history | edited | agavemelon | CC BY-SA 4.0 |
deleted 26 characters in body
|
| Apr 18, 2021 at 13:37 | comment | added | Mark_Bell | $s$ is the coordinate from origin. | |
| S Apr 18, 2021 at 13:37 | history | edited | agavemelon | CC BY-SA 4.0 |
Improved formatting
|
| S Apr 18, 2021 at 13:37 | history | suggested | Mark_Bell | CC BY-SA 4.0 |
Improved formatting
|
| Apr 18, 2021 at 13:35 | comment | added | Mark_Bell | When you do calculation you have to take one reference frame. In a circle there be a direction, just like in a segment. | |
| Apr 18, 2021 at 13:32 | comment | added | agavemelon | I understand, but this does not seem to answer my original question. So is ds/dt in fact a velocity and not speed (which I originally assumed it to be?) | |
| Apr 18, 2021 at 13:31 | review | Suggested edits | |||
| S Apr 18, 2021 at 13:37 | |||||
| Apr 18, 2021 at 13:30 | comment | added | mike stone | Velocity is ${\bf v}=d{\bf x}/dt$ and even in one dimension $dx$ can be negative just as $d\theta$ can be negative. In $s=\theta r$ both $s$ and $\theta$ can have either sign. This why $\omega$ is called the angular velocity not the angular speed. | |
| Apr 18, 2021 at 13:27 | comment | added | agavemelon | By my knowledge, velocity is a displacement vector differentiated over time, and speed is its magnitude. I still get the same problem. | |
| Apr 18, 2021 at 13:26 | comment | added | mike stone | You are missing the difference between speed and velocity. | |
| Apr 18, 2021 at 13:11 | history | asked | agavemelon | CC BY-SA 4.0 |