Calculating Rank Pulley Forces with Newton's Equations

  • Thread starter Thread starter isukatphysics69
  • Start date Start date
  • Tags Tags
    Forces Pulley rank
Click For Summary

Homework Help Overview

The discussion revolves around calculating forces in a system involving rank pulleys, specifically using Newton's equations. Participants are exploring the effects of friction, the setup of the problem, and the relationships between the masses involved.

Discussion Character

  • Mixed

Approaches and Questions Raised

  • Participants express confusion regarding the role of friction in the problem, with some suggesting to assume a frictionless surface. Others discuss the connections between the blocks and the pulley system, questioning how the forces and accelerations relate to each other.

Discussion Status

The conversation includes various attempts to derive equations for the forces and accelerations of the blocks. Some participants have provided guidance on the relationships between the tensions and accelerations, while others are still working through their calculations and interpretations.

Contextual Notes

There is an ongoing discussion about the assumptions made in the problem, particularly regarding the frictional forces and the ideal nature of the pulleys. Participants are also addressing the implications of the masses and their relationships in the context of the problem.

  • #31
ohhhhh wait a second i think i understand case A now
 
Physics news on Phys.org
  • #32
Ok so case A the acceleration is actually 9.8m/s^2
 
  • #33
So for big block = 2kg and small block = 1kg i have

A: acceleration = 9.8m/s^2
B: acceleration = 3.26m/s^2
C: acceleration = -6.55m/s^2
D: acceleration = -3.26m/s^2
E: acceleration = 0

so i put the ranking as A>B>E>D>C and it is incorrect
 
  • #34
isukatphysics69 said:
Ok so case A the acceleration is actually 9.8m/s^2
Why should it be 9.8 m/s2?
What is the tension? The tension accelerates the big box. What is the acceleration?
 
  • Like
Likes   Reactions: isukatphysics69
  • #35
isukatphysics69 said:
So for big block = 2kg and small block = 1kg i have

A: acceleration = 9.8m/s^2
B: acceleration = 3.26m/s^2
C: acceleration = -6.55m/s^2
D: acceleration = -3.26m/s^2
E: acceleration = 0

so i put the ranking as A>B>E>D>C and it is incorrect
A is wrong. What do you mean with negative accelerations? Use the magnitude of the acceleration to rank them.
 
  • Like
Likes   Reactions: isukatphysics69
  • #36
i am such an idiot i always rush things and make mistakes, so now i see that A is 4.9m/s^2
 
  • #37
Ok so the ranking is C > A > B = D > E
 
  • #38
Thank you for your patience ehild, i have completed the assignment finally.
 
  • #39
isukatphysics69 said:
Thank you for your patience ehild, i have completed the assignment finally.
You are welcome.
 
  • Like
Likes   Reactions: isukatphysics69

Similar threads

Ideal Vs Real Mass Pulley system
  • · Replies 10 ·
Replies
10
Views
5K
What is the ranking of forces in a problem on ranking forces?
  • · Replies 8 ·
Replies
8
Views
2K
Newton’s Law of Motions: tension forces in a pulley
  • · Replies 4 ·
Replies
4
Views
2K
Ranking Forces in Picture: Net Force and Friction Equations
  • · Replies 9 ·
Replies
9
Views
2K
Calc Forces on Pulleys: 200N, 300N Masses, No Friction
  • · Replies 1 ·
Replies
1
Views
2K
Pulley system problem: 6 Pulleys and 1 Mass
  • · Replies 5 ·
Replies
5
Views
1K
Force on a Cyclist: Net Force Calculation
  • · Replies 4 ·
Replies
4
Views
2K
'Force on pulley by a string' conception
  • · Replies 29 ·
Replies
29
Views
6K
Explain friction in a pulley system
  • · Replies 13 ·
Replies
13
Views
8K
Application of Newton's second law to a horizontal pulley
  • · Replies 2 ·
Replies
2
Views
1K