What is the relationship between x-t and v-t graph?

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SUMMARY

The discussion centers on the relationship between position-time (x-t), velocity-time (v-t), and acceleration-time (a-t) graphs. Participants debate the continuity of these graphs, particularly in cases where the x-t graph exhibits discontinuities. It is established that if the x-t graph is continuous, the corresponding v-t and a-t graphs must also be continuous. However, if discontinuities exist, vertical lines may be necessary to represent jumps in the graphs. The conversation emphasizes the importance of accurately interpreting the continuity of the x-t graph to correctly draw the related v-t and a-t graphs.

PREREQUISITES
  • Understanding of kinematics and graph interpretation
  • Familiarity with the concepts of continuity and differentiability in functions
  • Knowledge of how to derive velocity and acceleration from position graphs
  • Ability to analyze piecewise functions in graphical form
NEXT STEPS
  • Study the principles of continuity and differentiability in calculus
  • Learn how to derive velocity and acceleration from position-time graphs
  • Explore the concept of piecewise functions and their graphical representations
  • Practice drawing v-t and a-t graphs from various x-t graphs
USEFUL FOR

Students studying physics, particularly those focusing on kinematics, as well as educators and tutors looking to clarify the relationships between position, velocity, and acceleration graphs.

Optikspik
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I'm suppose to draw a v-t and a-t graph from a given x-t graph.

Here is the x-t graph and my attemps on the other two graphs from the x-t one.

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Howeverr

1. My teacher said that these graphs are discontinuous? Because I often see in littetaure that they drag "a vertical line" whenever something takes a jump, but it is discontinuous in the v-t graph right?

2. If it is discontinuous, and no vertical line down, If i was given the v-t graph and wanted to do a x-t rgaph. Then I would "imagine" a vertical line right? To calculate an area ?

3. Are these 2 graphs correct or what could be improved/ Whats wrong?
 
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Tbh it's rather poorly drawn, so my answer may be off.
The position time graph appears to be a piecewise function. However, if it is mentioned in the question that it is continuous, then by default the graphs of all its derivatives (velocity-time and acceleration-time) should be continuous, so you must draw those "jump" lines.
If the last section of the x-t graph is parabolic, then the other graphs are correct.
 
Pretty crude pictures. If I look at the lower two, I wonder how v can change from something to zero with a staying at zero...
 
PWiz said:
, if it is mentioned in the question that it is continuous, then by default the graphs of all its derivatives (velocity-time and acceleration-time) should be continuous
I'd like to contradict this. A continuous function doesn't have to be continuously differentiable...
 
BvU said:
I'd like to contradict this. A continuous function doesn't have to be continuously differentiable...
That is true in general, but I have yet to see a position time graph that has an undefined gradient.
EDIT: Unless you include some of those "jumps".
 
? I don't understand what any of u talking is about. will their be a vertical line down on v-t graph or is there "space" between?

this is not a queestion from a book, and u understand when i draw, Its just the "principle" not exact. Do i think right?
 
Optikspik said:
? I don't understand what any of u talking is about. will their be a vertical line down on v-t graph or is there "space" between?
Simply put - did the question say anything at all about the continuity of the x-t graph?
 
Optikspik said:
? I don't understand what any of u talking is about. will their be a vertical line down on v-t graph or is there "space" between?

this is not a queestion from a book, and u understand when i draw, Its just the "principle" not exact. Do i think right?
Ok, fair enough. let's restart:

Homework Statement



from a given x-t graph, draw a v-t and a-t graph (top pic in post #1)
given x(t) graph does not look like top pic ? could you post it, or describe the relevant details a little better ?

Homework Equations



?​

The Attempt at a Solution


[/B]
Lower two pictures in post #1
main barrier: continuity or not ? for x? for v ? for a ?​
- - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - -

What is, according to what you have learned, the relationship between x(t) and v(t) ?

and then we'll take it from there.

--
 

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