What is Change in velocity: Definition and 46 Discussions

Delta-v (more known as "change in velocity"), symbolized as ∆v and pronounced delta-vee, as used in spacecraft flight dynamics, is a measure of the impulse per unit of spacecraft mass that is needed to perform a maneuver such as launching from or landing on a planet or moon, or an in-space orbital maneuver. It is a scalar that has the units of speed. As used in this context, it is not the same as the physical change in velocity of the vehicle.
As a simple example, take a conventional rocket-propelled spacecraft which achieves thrust by burning fuel. The spacecraft's delta-v is the change in velocity that spacecraft can achieve by burning its entire fuel load.
Delta-v is produced by reaction engines, such as rocket engines, and is proportional to the thrust per unit mass and the burn time. It is used to determine the mass of propellant required for the given maneuver through the Tsiolkovsky rocket equation.
For multiple maneuvers, delta-v sums linearly.
For interplanetary missions, delta-v is often plotted on a porkchop plot, which displays the required mission delta-v as a function of launch date.

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  1. S

    Why is the integrated velocity times change in velocity zero?

    So consider a subject system, a galaxy, with stars in it. This galaxy is passed by another object, the perturber. When the interaction is fast, we call this interaction a high-speed encounter. Now we consider that the interaction is really fast. This means that during the interaction, the...
  2. SamRoss

    I How is the weak force related to a change in velocity?

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  3. P

    Finding the change in velocity through a potential difference

    We're given the equation qB=mv/r which is simple enough. I just don't know how to find the velocity given the acceleration through a potential difference. I tried using the radial acceleration equation given to me but I end up with the square root of a negative...and that breaks math... I...
  4. M

    Finding the change in velocity from an acceleration vs time graph

    Homework Statement The graph shows the variation with time t of the acceleration a of an object (graph attached). What is the change in velocity of the object in the time interval 0 to 4s? Homework Equations a = v/t The Attempt at a Solution My initial answer was -8 m/s, by simply finding the...
  5. K

    Can instantaneous velocity be different from average velocity?

    Homework Statement Is it possible for the instantaneous velocity of an object at some time, t1, to not be parallel to the average velocity over a short time interval, Δt=t2-t1? If it is not possible, explain why not. If it is possible, explain what this situation implies about the motion of...
  6. Sorcerer

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  7. Strange design

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    Good afternoon all, For those of you that teach physics, if an object has an initial velocity of - 5m/s and a final velocity of -20 m/s, do you consider the velocity to be increasing or decreasing in this case? I view this to be strictly defined mathematically, that is that the acceleration is...
  8. R

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  9. LoganNagol

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  10. Giu1iano

    Change in velocity due to force acting over given time

    What change in velocity would be produced by an unbalanced force of 2.4 × 10^4 N acting for 6 s on a 2.0 × 10^3 kg dragster? Not sure how to setup this problem Equations i have are as follows: Fnet = mass × acceleration Velocity2 = velocity1 + acceleration × time Distance = velocity1 × time +...
  11. x2017

    Change in Velocity after a Collision

    Homework Statement Kevin and Jake collide in the air. If Kevin undergoes a 4.2 kg*m/s change in momentum, what is Jacob’s change in velocity if he has a mass of 83.2 kg? Homework Equations p=mv MV+mv=MV'+mv' The Attempt at a Solution I tried the simplest way possible... p=mv v=p/m v=4.2/83.2...
  12. B

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  13. L

    Determine magnitude of change in velocity and direction

    Homework Statement A sailing boat moves at 12ms-1 due North then changing direction to north-west and traveling at a speed of 5.5ms-1 . Determine the magnitude of change in velocity n its direction. Homework EquationsThe Attempt at a Solution
  14. M

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  15. S

    Adding and Subtracting vectors; Finding change in velocity

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  16. Sneakatone

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  17. R

    How to find Change in velocity on an Acceleration vs TIme Graph?

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  18. N

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  19. J

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  20. N

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  21. F

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  22. M

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  23. B

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  24. P

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  25. P

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  26. B

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  27. D

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  28. U

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  29. W

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  30. S

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  31. G

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  32. M

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  33. K

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  34. D

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  35. L

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  36. P

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  37. D

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  38. S

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  39. Y

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  40. E

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  41. H

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  42. K

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  43. C

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  44. M

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  45. R

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  46. N

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