Tangential Velocity (maybe)

Click For Summary

Discussion Overview

The discussion revolves around the concept of tangential velocity in the context of circular motion, specifically focusing on the relationship between two points, A and B, rotating around a common center. Participants explore the necessary conditions and information required to calculate the tangential velocity of point B, including angular velocities and initial positions.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants propose that the tangential velocity of point B can be derived from the angular velocities and positions of points A and B.
  • Others argue that additional information, such as the initial positions of A and B, is necessary to calculate the tangential velocity accurately.
  • A participant suggests using "o'clock" positions to describe the locations of points A and B on their respective circles.
  • There is a discussion about whether the linear velocities of A and B can simply be added together, with some participants expressing uncertainty about this approach.
  • Some participants emphasize the importance of using symbols and algebraic expressions rather than numerical values for clarity in calculations.
  • One participant mentions that the problem can be solved using vectors and their derivatives, although they note that the final expression may be complex.
  • Historical context is introduced, referencing Ptolemy's geocentric model and Newton's contributions to calculus in understanding planetary motion.

Areas of Agreement / Disagreement

Participants express differing views on the necessity of vector analysis and the complexity of the problem. While some agree on the importance of initial conditions, others question the need for vector representation, leading to an unresolved discussion about the best approach to solving the problem.

Contextual Notes

There are limitations regarding the assumptions made about the positions and angular velocities of points A and B, as well as the dependency on definitions of tangential velocity and angular velocity. The discussion also reflects varying levels of mathematical background among participants, which affects their ability to engage with the problem.

  • #31
kuruman said:
What additional description do you require?
Actually I want to know why B will start rotating?
 
Physics news on Phys.org
  • #32
I assume that vector A rotates about the origin, referenced to the x-axis.
Does vector B rotate relative to vector A, or relative to the x-axis ?

Which tangential velocity is required? Is it the rate of point B about the origin in rad/sec, or distance per second about the origin.
Or is it the instantaneous velocity of point B on the x, y plane ?

titasdasplus said:
Actually I want to know why B will start rotating?
Because it is specified as having an angular frequency.
What alternatives are there?
 
  • #33
haruspex said:
In that thread, I did show that the expression gave the right answer in a couple of special cases. Maybe you would find that more persuasive?
You were right, and my "suspicion" was wrong. I misinterpreted the requirement in the OP (see the "edit" in post #29).
 
Reply
  • Like
Likes   Reactions: haruspex
  • #34
kuruman said:
Around 200 CE, Ptolemy came close to describing planetary motion within the geocentric model. He used the idea of epicycles which is essentially what we have here
Well, in this case we're describing the orbit of the Moon...
 

Similar threads

Undergrad Understanding the Coriolis force
  • · Replies 2 ·
Replies
2
Views
490
Is My Calculation of Centripetal Acceleration and Tangential Velocity Correct?
  • · Replies 12 ·
Replies
12
Views
2K
High School What gives satellites their tangential velocity?
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Tangential velocity of an object rotating around a rotating axis
  • · Replies 5 ·
Replies
5
Views
2K
High School Static friction needed for rolling without slipping
  • · Replies 4 ·
Replies
4
Views
2K
High School How is tangential velocity measured in m/s when it’s r * w?
  • · Replies 41 ·
2
Replies
41
Views
3K
Undergrad A high school physics problem demonstrating relative motion
  • · Replies 6 ·
Replies
6
Views
990
Undergrad Does a rotating accelerometer moving linearly measure linear velocity?
  • · Replies 47 ·
2
Replies
47
Views
5K
Projectile motion, initial height and range given, find initial velocity
  • · Replies 8 ·
Replies
8
Views
2K
High School What is physical significance of the direction of angular velocity?
  • · Replies 2 ·
Replies
2
Views
2K