- #1
svqweasdzxc
- 2
- 0
I am not clear about the concept about relative angular velocity.
So i can't solve the first question
please help me
Question about relative angular velocity
- Thread starter svqweasdzxc
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Homework Help Overview
The discussion revolves around the concept of relative angular velocity, particularly in the context of celestial objects such as Earth and a Kuiper Belt Object (KBO). Participants are attempting to understand how to apply the concept to a specific problem involving angular and linear speeds.
Discussion Character
- Conceptual clarification, Assumption checking, Mixed
Approaches and Questions Raised
- Participants are exploring the definition of relative angular velocity and its application to a problem involving the motion of celestial bodies. There are attempts to relate angular speed to linear speed and to clarify how these concepts interact.
Discussion Status
Some participants have offered insights into the relationship between angular and linear speeds, suggesting a shift in perspective to facilitate understanding. However, there is still uncertainty among participants regarding the application of these concepts, and no consensus has been reached.
Contextual Notes
Participants express confusion about the relative nature of angular velocity and its implications in the problem context. There are indications of varying levels of familiarity with the topic, and some participants have noted language barriers that may affect communication.
I am not clear about the concept about relative angular velocity.
So i can't solve the first question
please help me
- #2
tiny-tim
Science Advisor
Homework Helper
- 25,837
- 258
welcome to pf!
hi svqweasdzxc! welcome to pf!
relative angular velocity of A relative to B is dθ/dt, where r and θ are the position of A, measured in a polar coordinate system whose origin is at B
(or, more realistically, it's the angular speed with which the kuiper belt object moves across the background stars!
)
hi svqweasdzxc! welcome to pf!
svqweasdzxc said:
relative angular velocity of A relative to B is dθ/dt, where r and θ are the position of A, measured in a polar coordinate system whose origin is at B
(or, more realistically, it's the angular speed with which the kuiper belt object moves across the background stars!
)- #3
svqweasdzxc
- 2
- 0
but i still don't know how to solve this problem,sorry.
please forget my stupidity
please forget my stupidity
- #4
G.I.
- 4
- 0
Hi,
try to move the problem from angular speed to "linear" speed. The Earth moves with speed Ve, the KBO with speed V, so the relative speed between Earth and KBO is Ve - V.
Now, the "linear" speed can be rewritten as the angular speed times the radius, so we can write the relative speed as the distance between Earth and KBO multiplied by the relative angular speed (Vrel=Ve-V = ω(r-1)[AU]). Here your resoult.
(Note that this is true only in the case opposition or if r>>1)
I apologize for (really) possible English mistakes, I need a bit of training about that.
try to move the problem from angular speed to "linear" speed. The Earth moves with speed Ve, the KBO with speed V, so the relative speed between Earth and KBO is Ve - V.
Now, the "linear" speed can be rewritten as the angular speed times the radius, so we can write the relative speed as the distance between Earth and KBO multiplied by the relative angular speed (Vrel=Ve-V = ω(r-1)[AU]). Here your resoult.
(Note that this is true only in the case opposition or if r>>1)
I apologize for (really) possible English mistakes, I need a bit of training about that.
- #5
Basic_Physics
- 358
- 6
This relative business is always difficult. Think of the hands of an analog watch. Both are moving. The hour hand slower than the minute hand. If someone (very small) was to sit on the minute hand it would seem to him that the hour hand is rotating anticlockwise, that is away from the hour hand, although it is actually moving clockwise. This apparent anticlockwise rotation of the hour hand is the motion relative to the minute hand. It is the difference between the two motions that creates the relative motion.