Two masses m1=5 kg and m2=9 kg are connected by a string which passes over

  • Thread starter Thread starter Abdlellah
  • Start date Start date
  • Tags Tags
    String Two masses
Click For Summary

Homework Help Overview

The problem involves two masses, m1 and m2, connected by a string over a massless, frictionless pulley. The scenario includes kinetic friction acting on m1, and participants are tasked with calculating the acceleration of both masses and the tension in the string.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the forces acting on the masses, including gravitational and frictional forces. There are inquiries about the initial intuition regarding the problem and the main principles to apply. Some participants express uncertainty about their calculations and seek clarification on the approach to finding acceleration and tension.

Discussion Status

The discussion is ongoing, with some participants attempting calculations while others provide guidance on considering all forces involved. There is a recognition of the need to account for friction and the total mass in the system. However, there is no explicit consensus on the correct approach or final answers.

Contextual Notes

Participants are encouraged to explore their reasoning and clarify their understanding without receiving direct answers. The nature of the homework context emphasizes learning through discussion rather than providing complete solutions.

Abdlellah
Messages
12
Reaction score
0

Homework Statement



two masses m1=5 kg and m2=9 kg are connected by a string which passes over a massless frictionless pulley. the masses are moving with an acceleration a as shown. the coefficient of kinetic friction between m1 and surface of the table is 0.1 calculate the acceleration of block 1, the acceleration of block 2 and the tension in the string.

http://t0.gstatic.com/images?q=tbn:...phsGvO7lUMigQiON8sOud2-zoII78Enu2kNXFs1XNGIdg

Homework Equations





The Attempt at a Solution

 
Physics news on Phys.org
You don't show any attempt at a solution, are you completely lost?

What is your first intuition? What forces are at work here? What is the main principal that we should use regarding forces?
 
You don't show any attempt at a solution, are you completely lost?

What is your first intuition? What forces are at work here? What is the main principal that we should use regarding forces?
 
i answered the first box like that but I am not sure
a= (Fa - Fr)/m
a= 49-4.9/(5) = 8.82
because it is in the X axis so no angle.

in the second part i don't know what i should do
 
Almost the right way to find the acceleration but you are calculating the forces incorrectly.

Ok, here is what you have to do, consider all the forces at play here, there is the gravity force pulling on both the masses but only one of the gravity forces causes the masses to move, the gravity force on mass 1 is the same as the normal force on mass 1 which leads to a friction force that deters the acceleration. So you need to find the total force on the system (by subtracting the friction force from the gravitation force that is causing the movement) and that will be equal the total mass (not only the 5kg) times the acceleration that you are searching for.
 
Almost the right way to find the acceleration but you are calculating the forces incorrectly.

Ok, here is what you have to do, consider all the forces at play here, there is the gravity force pulling on both the masses but only one of the gravity forces causes the masses to move, the gravity force on mass 1 is the same as the normal force on mass 1 which leads to a friction force that deters the acceleration. So you need to find the total force on the system (by subtracting the friction force from the gravitation force that is causing the movement) and that will be equal the total mass (not only the 5kg) times the acceleration that you are searching for.
 
Could u please tell me the final answer ?
 
Unfortunately for you that's not how we do things around here.
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
Replies
21
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 47 ·
2
Replies
47
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
17
Views
2K
Replies
16
Views
2K
Replies
2
Views
2K
  • · Replies 33 ·
2
Replies
33
Views
3K
  • · Replies 17 ·
Replies
17
Views
3K