Energy conservation in circular motion

Click For Summary

Homework Help Overview

The problem involves an object of mass moving along a circular frictionless path and seeks to determine the normal force at a specific point when released from rest. The context includes concepts of energy conservation and forces in circular motion.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the application of energy conservation principles, questioning the validity of certain equations used in the attempts. There is a focus on clarifying variables and correcting typographical errors in the equations presented.

Discussion Status

The discussion is ongoing, with participants providing feedback on each other's attempts. Some have identified mistakes in the reasoning and calculations, while others have offered corrections and clarifications. There is no explicit consensus on the final answer yet.

Contextual Notes

Participants are working under the constraints of a homework assignment, which may limit the information available for solving the problem. The specific angle and initial conditions are critical to the discussion.

Fatima Hasan
Messages
315
Reaction score
14

Homework Statement


An object of mass m = 1 kg moves along a circular frictionless path of radius R = 0.5 m from point A to point B at which it makes an angle θ with the vertical direction as shown in the figure. If the object is release from rest (VA = 0) and θ = 30° , what is the normal force at point B (in N) ?
upload_2018-1-6_16-25-52.png


A ) 2.98 B) 25.98 C) 28.19 D) 29.54

Homework Equations


gif.gif


3. The Attempt at a Solution [/B]
Here's my work :
%5CF%3Dma%5C%5CF%3D2.67%20N%5C%5Cmg%20cos%20%5CTheta%20-FN%3D2.67%5C%5C8.6-FN%3D2.67%5C%5CFN%3D5.gif
 

Attachments

  • upload_2018-1-6_16-25-52.png
    upload_2018-1-6_16-25-52.png
    24.8 KB · Views: 1,031
  • gif.gif
    gif.gif
    1 KB · Views: 922
  • %5CF%3Dma%5C%5CF%3D2.67%20N%5C%5Cmg%20cos%20%5CTheta%20-FN%3D2.67%5C%5C8.6-FN%3D2.67%5C%5CFN%3D5.gif
    %5CF%3Dma%5C%5CF%3D2.67%20N%5C%5Cmg%20cos%20%5CTheta%20-FN%3D2.67%5C%5C8.6-FN%3D2.67%5C%5CFN%3D5.gif
    9.9 KB · Views: 1,026
Physics news on Phys.org
Fatima Hasan said:

Homework Statement


An object of mass m = 1 kg moves along a circular frictionless path of radius R = 0.5 m from point A to point B at which it makes an angle θ with the vertical direction as shown in the figure. If the object is release from rest (VA = 0) and θ = 30° , what is the normal force at point B (in N) ?
View attachment 217967

A ) 2.98 B) 25.98 C) 28.19 D) 29.54

Homework Equations


View attachment 217968

3. The Attempt at a Solution [/B]
Here's my work :
View attachment 217969
Your work is wrong. What is k?
You can not write gh=gh+0.5v^2. It means that the v2=0.
 
ehild said:
Your work is wrong. What is k?
You can not write gh=gh+0.5v^2. It means that the v2=0.
K is a typo. It should be m
gh1 = gh2 + 0.5 v^2
 
Fatima Hasan said:
K is a typo. It should be m
gh1 = gh2 + 0.5 v^2
It is better now, but your v2is wrong.
 
ehild said:
It is better now, but your v2is wrong.
I found the mistake. The height in B, I should substract it from 0.5
The answer is 25.98
 
Fatima Hasan said:
I found the mistake. The height in B, I should substract it from 0.5
The answer is 25.98
Well done!
 
  • Like
Likes   Reactions: Fatima Hasan

Similar threads

Replies
8
Views
2K
Replies
20
Views
2K
  • · Replies 29 ·
Replies
29
Views
2K
Replies
11
Views
3K
  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 12 ·
Replies
12
Views
3K
  • · Replies 6 ·
Replies
6
Views
2K
Replies
15
Views
2K
Replies
6
Views
4K
  • · Replies 29 ·
Replies
29
Views
2K