- #1
svqweasdzxc
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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
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Relative angular velocity is defined as the rate of change of angle (dθ/dt) of one object in relation to another, typically measured in a polar coordinate system. To understand this concept better, one can convert angular speed to linear speed, where the relative speed between two objects can be expressed as the difference in their velocities. The discussion uses the example of Earth and a Kuiper Belt Object (KBO) to illustrate how relative speeds can be calculated. An analogy with clock hands is provided to clarify how relative motion works, emphasizing that the apparent motion of one object can differ from its actual motion due to the influence of another object's movement. Understanding these principles is crucial for solving problems related to relative angular velocity.
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
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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
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but i still don't know how to solve this problem,sorry.
please forget my stupidity
please forget my stupidity
- #4
G.I.
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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.