Kinematics - how do u find distance travelled

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Homework Help Overview

The discussion revolves around finding the distance traveled in a kinematics context, specifically using velocity and displacement functions over a defined time interval.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants explore the use of definite integrals to calculate distance traveled, questioning whether to use the integral of velocity or the absolute value of velocity. There is discussion about the implications of negative velocity on distance calculations.

Discussion Status

Participants are actively engaging with the concepts, with some providing clarifications on the necessity of using the absolute value of velocity. There is acknowledgment of the complexity involved in integrating modulus functions, and a general agreement on the approach to take when analyzing a parabola graph of displacement over time.

Contextual Notes

Participants mention the potential for the object to change direction, which affects the calculation of distance versus displacement. There is also a reference to previous experience with modulus functions, indicating a varying level of familiarity with the topic among participants.

meee
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ok. so i have x(t) = something and v(t) = something

i know x will give me the displacement for a set time

say if i wanted the distance traveled in the first ten seconds, i know i can use the definite integral of velocity.

Is there any easier way? like using the displacement equation?
 
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Actually you can't use the definite integral of velocity-you have to use the definite integral of the absolute value of velocity or else you'd be measuring displacement and not distance. You don't want the distance traveled to start decreasing just because the velocity becomes negative.

Since it is in 1 dimension, if it never turns around, then its distance traveled after 10 seconds is the absolute value of its position after 10 seconds. If it does turn around and double back on its path then what can you say about the distance?
 
then it would be double!

lol ok... so if i have like a parabola graph of displacement/time i can just add up from the y values of start to max/mins and end point etc.
 
As orthodontist said, you must use the integral of the modulus of your function of velocity;

[tex]\int^{10}_{0} \left| v(t) \right| dt[/tex]

The process is quite laborious and not one of my favourite things to do, have you solved modulus functions before?
meee said:
so if i have like a parabola graph of displacement/time i can just add up from the y values of start to max/mins and end point etc.
Yes, that would work :smile: (I think)
 
sweet thanks guys
yeah I've done modulus functions
 

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