Changing V(x) to V(t): Chain Rule Application?

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Discussion Overview

The discussion revolves around the process of converting a velocity function expressed in terms of position, V(x), into a function of time, V(t). Participants explore the application of the chain rule and integration techniques in this context.

Discussion Character

  • Exploratory, Technical explanation, Mathematical reasoning

Main Points Raised

  • One participant presents a velocity function of the form V(x) = a*x² + b*x + c and seeks guidance on how to express it as V(t).
  • Another participant suggests that since V represents the derivative of position with respect to time, one can derive dt in terms of dx and then integrate to find t as a function of x, followed by solving for x as a function of t.
  • A third participant emphasizes that velocity is derived from differentiating a position equation and mentions the options of integrating or finding the antiderivative to reverse the process.
  • A later reply confirms the assumption that t represents time and reiterates the integration approach, noting that the participant successfully performed the integration and solved for x.

Areas of Agreement / Disagreement

Participants generally agree on the approach of using integration to convert V(x) to V(t), but there are variations in the details of the methods suggested. The discussion does not reach a consensus on a single method, as different participants provide slightly different perspectives on the process.

Contextual Notes

Some limitations include the dependence on the initial conditions provided and the specific form of the velocity function. The discussion does not resolve any potential complexities in the integration process or the assumptions made about the functions involved.

Who May Find This Useful

This discussion may be useful for students or individuals interested in understanding the relationship between velocity, position, and time, particularly in the context of calculus and physics.

StephenSF8
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I have a function for velocity, V in terms of position, x. The equation is of the form V(x) = a*x2+b*x+c. Initial conditions are x=0, t=0.

How do I change from V(x) to V(t)? It seems this would be an application of the chain rule, dy/dx = dy/du * du/dx, but I'm struggling to adapt it to this situation. Am I way off base?

Thanks!
 
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Assuming t means time, then V=dx/dt. So dt = dx/(a*x2+b*x+c). Integrate both sides to get t as a function of x. Solve for x as a function of t. Then take the derivative to get V. Good luck!
 
Velocity is the result of differentiating a position equation. To reverse that you have two options, (the same pretty much): Integrate or find the Antiderivative.

Enjoy.
 
mathman said:
Assuming t means time

You assume correct.

mathman said:
Integrate both sides to get t as a function of x. Solve for x as a function of t.

This is what I was missing. I was able to perform the integration and solve for x and all is well. Thanks for the help!
 

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