I got a question about relative velocities

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Discussion Overview

The discussion revolves around the concept of relative velocities, specifically how the velocity of one object (B) is perceived from another object's (A) frame of reference, and vice versa. Participants explore the implications of changing the reference frame and the significance of directional axes in these calculations.

Discussion Character

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

Main Points Raised

  • Some participants state that if the velocity of B relative to A is +10 m/s, then the velocity of A relative to B will be -10 m/s.
  • Others argue that both A and B can consider their own velocity to be zero, leading to a situation where they perceive each other as moving at 10 m/s.
  • A participant questions the meaning of "along some axis" in the context of relative velocity, indicating a need for clarification on directional components.
  • One participant emphasizes that a velocity value, such as -10 m/s, is meaningful only when defined with respect to a specific direction.

Areas of Agreement / Disagreement

Participants generally agree on the principle that relative velocities are dependent on the chosen frame of reference. However, there is some confusion regarding the implications of directional axes, indicating that the discussion remains partially unresolved.

Contextual Notes

The discussion includes assumptions about the reference frames and the interpretation of velocity directions, which are not fully elaborated. The implications of these assumptions on the understanding of relative motion are not resolved.

q2501
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velocity of B relative to A is -10 m/s or 10 m/s

i am very confusing this. if i change the question to velocity of A relative to B , IS the answer same as above?~
 
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If the velocity of B relative to A is +10 m/s along some axis, then the velocity of A relative to B will be -10 m/s.
 
Yes, as Doc has said. Both A and B can consider their own velocity to be zero. They both consider the other to be the one going 10 m/s. There is no law of physics that allows you to make an absolute distinction between who is moving and who is not.
 
Doc Al said:
If the velocity of B relative to A is +10 m/s along some axis, then the velocity of A relative to B will be -10 m/s.
what do you mean by along some axis
 
my_wan said:
Yes, as Doc has said. Both A and B can consider their own velocity to be zero. They both consider the other to be the one going 10 m/s. There is no law of physics that allows you to make an absolute distinction between who is moving and who is not.

Thank you i got it
 
q2501 said:
what do you mean by along some axis
A velocity such as -10 m/s only makes sense with respect to some direction.
 

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