Graphs of s, v and a for a mass with a piece of paper attached

AI Thread Summary
The discussion centers on understanding the graphs of position, velocity, and acceleration for a mass with a piece of paper attached, which may represent a damped harmonic oscillator. Participants express confusion about how to sketch these graphs over a time period of 2T, particularly regarding the impact of the piece of paper on the net force. It is noted that the graphs should vary sinusoidally, but the introduction of damping complicates the representation. Suggestions are made to derive the velocity and acceleration graphs from the position graph, emphasizing that the velocity graph is the slope of the position graph and the acceleration graph is the slope of the velocity graph. Overall, there is a call for clarity on how to accurately model and sketch these graphs in the context of damping.
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Homework Statement
Hello, I am really struggling to sketch the following graphs to show how a mass with a piece of paper attached to it varies with time, over a time period of 2T, for: 1. Energy 2. Displacement 3. Velocity 4. Acceleration
Relevant Equations
x=Acosωt v=-ωAsinωt a=-ω^2Acosωt
I understand that velocity is defined as the rate of change of position or the rate of displacement; and that acceleration is defined as the rate of change of velocity (it is the derivative of velocity).
Morever, I believe I know that for SHM these graphs vary sinusoidally (I have attached a picture of how I think these should appear).
However, for a mass with a piece of paper attached could these graphs be represented by a harmonic oscillator with a small amount of damping? I really do not know where to begin in drawing these, I am very confused.
 

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  • Screenshot 2021-04-13 at 19.40.02.png
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It's not clear what is the significance of the piece of paper! Is this a translation?
 
PeroK said:
It's not clear what is the significance of the piece of paper! Is this a translation?
I have no idea, I really am very confused. The question just states " Sketch the following graphs to show how a mass with a piece of paper attached to it varies with time, over a time period of 2T"
 
So, the net force is no longer a constant...
you need to model the new net force... a constant plus a new contribution.

If it were damped, what would a sketch of the position-vs-time graph look like?
From that get the other two
[velocity-vs-time is a graph of the slopes of the position-vs-time graph,
acceleration-vs-time is a graph of the slopes of the velocity-vs-time graph
https://phet.colorado.edu/en/simulation/legacy/calculus-grapher [uses Flash]
Not quite as arbitrary as above (but more constructive]:
https://www.geogebra.org/m/dzxdbzAR
https://www.geogebra.org/m/ezKv36tC
]
Or one could work from the acceleration-vs-time [since you know the net force], then get the other two.

Possibly helpful.
https://www.wired.com/2017/04/lets-study-air-resistance-coffee-filters/
 
robphy said:
So, the net force is no longer a constant...
you need to model the new net force... a constant plus a new contribution.

If it were damped, what would a sketch of the position-vs-time graph look like?
From that get the other two
[velocity-vs-time is a graph of the slopes of the position-vs-time graph,
acceleration-vs-time is a graph of the slopes of the velocity-vs-time graph
https://phet.colorado.edu/en/simulation/legacy/calculus-grapher [uses Flash]
Not quite as arbitrary as above (but more constructive]:
https://www.geogebra.org/m/dzxdbzAR
https://www.geogebra.org/m/ezKv36tC
]
Or one could work from the acceleration-vs-time [since you know the net force], then get the other two.

Possibly helpful.
https://www.wired.com/2017/04/lets-study-air-resistance-coffee-filters/
Thank you for your reply. I have attached what I think the displacement tie graph for a draped oscillator would look like. However, I am uncertain how to find the v-t and a-t graphs from this? Would this be correct anyhow for the s-t graph?
 

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  • Screenshot 2021-04-13 at 21.52.11.png
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And would the energy-time graph for a damped oscillator be as shown in the attachment ?
 

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  • Screenshot 2021-04-13 at 21.55.52.png
    Screenshot 2021-04-13 at 21.55.52.png
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Thread 'Variable mass system : water sprayed into a moving container'
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