Does the Bead's Speed Change as It Slides Along a Frictionless Curve?

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Homework Help Overview

The problem involves a bead sliding along a frictionless curved wire in a vertical plane, starting from rest. Participants are tasked with evaluating the truth of several statements regarding the bead's acceleration and speed at different points along the curve, particularly focusing on points A, C, and H.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • The original poster attempts to analyze the relationship between potential energy and kinetic energy at various points, questioning the validity of their reasoning for each statement. Some participants express concerns about the clarity of the diagram and its impact on understanding the problem.

Discussion Status

The discussion is ongoing, with the original poster seeking validation for their reasoning on the statements. Some guidance has been offered regarding the need for a visual aid, and the original poster has attempted to clarify the situation by providing a link to the diagram.

Contextual Notes

There is a noted absence of the diagram initially, which may have hindered some participants' ability to engage fully with the problem. The original poster expresses uncertainty about their conclusions and seeks feedback on their thought process.

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Homework Statement


The figure below shows a bead sliding without friction along a curved wire in a vertical plane.
IMAGE: http://img545.imageshack.us/i/bead.png/

The bead slides starting from rest at position B on the frictionless wire. The direction of the gravitational field is in the -y direction (toward the bottom of the page).

I then have 6 statements that I have to determine if they are true, false, greater than, less than, or equal to:

1.) The acceleration in the x-direction at H is ... zero.
2.) The speed at C is ... the speed at A.
3.) The acceleration in the y-direction at H is ... zero.
4.) The acceleration at C is zero.
5.) The velocity at A equals the velocity at C.
6.) The speed at H is ... the speed at C.

Homework Equations


change KE + change PE = 0


The Attempt at a Solution


I feel confident for numbers 2, 5, and 6.

2 - Points C and A appear to be at the same height which means their PE is the same which means their KE are the same. Equal To

5 - While the speeds may be the same (for the same reason as 2) the velocity also takes into account the direction, which isn't the same in this case. False

6 - H is lower than C, which means there is a greater amount of potential energy at C. Greater Than

Now for 1, 3, and 4.

1 - It appears to be at the bottom of the curve. As the bead is descending the bead is gaining speed in the x direction, and as the the bead is ascending the bead is losing speed. It has to change signs at some point which means it has to equal zero at the bottom. Equal To

3 - The speed increases rapidly as the bead first falls and then tapers off until the speed downwards is zero. The acceleration must be towards the positive Y direction then? Greater Than

4 - In this case both accelerations (X and Y directions) must be taken into account. I believe the acceleration in the X direction is still zero because of the same line of reasoning as 1. Acceleration in the -Y direction should actually be increasing though. False

Is there anything wrong with my way of thinking? I just don't feel overly confident in my answers.

Thanks a bunch!
 
Last edited by a moderator:
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panx said:
The diagram is missing. :( or else I would have tried.
If you want somebody to explain it on a white-board, you can take live online help offered by www.myphysicsbuddy.ca[/URL]. I used the free demo given and they are good at such stuffs.
Let me know if it helps.
Cheers[/QUOTE]
The picture doesn't show up?

[ATTACH=full]140319[/ATTACH]
 

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Last edited by a moderator:
Well I added the link to the picture. Hope that works. Thanks for your offer, but I'm too cheap to pay for help :P (I can see I get one free trial)
 
Figured it out :approve:
 
Last edited by a moderator:

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