What is Relative motion: Definition and 282 Discussions

The relative velocity







v
→




B
∣
A




{\displaystyle {\vec {v}}_{B\mid A}}
(also







v
→




B
A




{\displaystyle {\vec {v}}_{BA}}
or







v
→




B
rel
⁡
A




{\displaystyle {\vec {v}}_{B\operatorname {rel} A}}
) is the velocity of an object or observer B in the rest frame of another object or observer A.

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  1. U

    Relative Motion of a Motorcyclist on a Rotating Bike

    Homework Statement A motorcyclist accelerates rapidly so the bike entirely rests on the back wheel, while the midpoint of the back wheel O' accelerates with constant acceleration a_o' horizontally. The entire bike rotatoes with angular velocity \frac{d}{dt} \theta and angular acceleration...
  2. NATURE.M

    Will the Ice Cream Land on Your Professor's Head? Exploring Relative Motion

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  3. H

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    Homework Statement An airplane has a velocity 325km/h relative to the air. It is going in a direction [S30W]. There is a wind velocity of 80km/h[W]. What is the velocity of the plane relative to the ground? Homework Equations aVg + pVa = pVg (velocity of air relative to ground +...
  4. J

    Vector / Relative Motion Problem

    Homework Statement A pilot flying East from Hartford to Providence (distance of 50 miles) releases a balloon directly over Providence. 15 minutes later, the pilot turns around. The pilot sees the balloon again over Hartford. What is the approximate wind velocity? (Assume constant airspeed...
  5. S

    Solve 1D Relative Motion Homework: Ball Thrown, Elevator, Tennis & Baseballs

    Homework Statement 1)A ball is dropped from the top of a 56.0 m-tall building. After 2.00 s, another ball is thrown upward from the ground. When the two balls pass the same point, they have the same speed. How fast was the upward-bound ball thrown? 2)You are riding an elevator with an...
  6. S

    One Dimentional Relative Motion

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  7. M

    Reference frame in relative motion

    I red a classical mechanics concept in a book. Imagine that we have two observers with two frames of reference F1 and F2 observing a particle P in motion. One of the observer is in motion and another is at rest,(lets take F1 is at rest and F2 is in translation motion with velocity V) let r1 be...
  8. C

    Dynamics - relative motion, planes Q

    Homework Statement Aircraft A is describing a circular flight path in an anti-clockwise direction at 125km/h Aircraft B is flying the same path but in the opposite direction at 225km/h. If the radius of the flight path is 5km, calculate the acceleration of A relative to B when Aircraft A is...
  9. J

    Confused by Relative Motion? Get Answers Here!

    Disclaimer: This is not for any class. I have downloaded this book ( http://www.ck12.org/book/CK-12-Physics---Intermediate/ ) and am ( attempting to (: ) work through it on my own. I am going through the section on relative motion ( section 3.3 in the book ) and am confused by a portion. It...
  10. A

    Using relative motion (2D) to get rain speed & direction when running

    Homework Statement A person moving towards east with a speed 'v' observes the rain to be falling vertically downwards. When he doubles his speed, the rain appears to come at 30° angle with the vertical. Find the actual speed and direction of rain with vertical. Homework Equations...
  11. V

    Is relative motion different from acceleration?

    I saw someone post a question or a comment about relative motion and acceleration. It got me thinking about the spaceship in deep space with rocket boosters. Well, when that guy or girl hits the booster, he or she accelerates, but the person is not necassarily moving relative to anything. Is...
  12. S

    Question about relative motion: 3 Golden Retrievers in deep space

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  13. M

    What direction will a man appear to be rowing in relative motion?

    Hello, If a man how is able to row on still water at 2.5m/s. If the water is moving at 1.5m/s, in which direction should he row. The answer is he should row at 53.1 degrees upstream but the question for an observer on the boat and another observer on land, how will the motion appear? For an...
  14. R

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  15. P

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    Homework Statement A body consisting of two spheres attached by a 10 meter solid long rod is rolling down a 45 degree incline at one end while rolling up a 45 degree incline on the other end. At the instant when the connecting rod is horizontal the sphere rolling down has the velocity 2 m/s...
  16. A

    What is your velocity when walking on a moving train in the opposite direction?

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  17. Q

    Simple Relative Motion Problem

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  18. S

    How Does Moving at 20sqrt(2) m/s Affect the Projectile's Trajectory Equation?

    Homework Statement To an observer not in motion in the ground, the trajectory of a projectile is described by: y = x - 10^{-3}x^2(In SI units) Where it was adopted x = 0 and y = 0 for the origin point. Determine the trajectory equation for an observer that moves at 20sqrt(2) m/s in relation to...
  19. L

    Physics - Relative Motion Homework Help

    Homework Statement A ferryboat, whose speed in still water is 4.00m/s, must cross a river whose current is 3.00m/s. The river runs from west to east and is 128m wide. The boat is pointed north. a) If the boat does not compensate for the flow of the river water and allows itself to be...
  20. P

    Two dimensional relative motion; boat and river problem

    Homework Statement Mary needs to row her boat across a 100-m-wide river that is flowing to the east at a speed of 1.0 m/s. Mary can row with a speed of 2.0 m/s. a) If Mary points her boat due north, how far from her intended landing spot will she be when she reaches the opposite shore? b)...
  21. P

    Question about pulley with relative motion

    for part(i) the answer is g/4 + g/2 = 3g/4 ms^-2 how to calculate the acceleration of the 9N blcok relative to the small pulley to be g/4?? Did I miss something? thank you so much!o:)
  22. C

    Relative motion of train and platform observer

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  23. P

    Relative Motion 1D: Collisions

    Homework Statement A mosquito flies toward you with a velocity of 2.2 km/h (E). If you are traveling toward the mosquito with a speed of 1.9 m/s, and a distance of 21.0 m separates you and the mosquito initially: A) What will your displacement be when you hit the mosquito? (7) B) How long...
  24. D

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  25. T

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  26. X

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  27. S

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  28. coktail

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  29. J

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  30. I

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  31. S

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  32. S

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  33. C

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  34. A

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  35. T

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  36. T

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  37. S

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  38. R

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    Homework Statement While driving north at 25 during a rainstorm you notice that the rain makes an angle of 38 with the vertical. While driving back home moments later at the same speed but in the opposite direction, you see that the rain is falling straight down. a)From these observations...
  39. A

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  42. U

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  43. N

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  44. D

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  45. B

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  46. S

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  47. F

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  48. C

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    Im reading a page out of Griffiths about 2 guys holding a wire loop on a railroad car and then traveling through a B field on the track. As the guys travel at a speed v through the B field the electrons will start to move in the conductor. If we view it from the point of the the B field...
  49. L

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  50. L

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