Two Masses and the Tension in a rod

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Homework Help Overview

The problem involves two masses connected by a massless rod on an inclined plane, with specific values for mass, angle of incline, and coefficients of kinetic friction. The objective is to determine the tension in the rod connecting the two masses.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts to calculate the tension by considering forces acting on each mass, including friction and gravitational components. Some participants question the relationship between the tensions in the rod and the implications of massless rod dynamics.

Discussion Status

The discussion is ongoing, with participants exploring different interpretations of the tension in the rod. Some guidance has been offered regarding the action-reaction principle, but no consensus has been reached on the calculations or the correct approach.

Contextual Notes

Participants are working under the constraints of the problem statement, with no provided answers or definitive methods for verification. The original poster expresses uncertainty about their calculations and seeks validation.

Rohaaan
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Homework Statement



Two masses, m1 = 1.65kg and m2 = 3.30kg, attached by a massless rod parallel to the inclined plane on which they both slide, travel along the plane with m1 trailing m2. The angle of incline is 30°. The coefficient of kinetic friction between m1 and the incline is μ1 = 0.226; that between m2 and the incline is μ2 = 0.113.

What is the tension in the rod?

Homework Equations



Ff = μk × FN

FN = mgcosθ

The Attempt at a Solution



So, for m1:

Ff1 = μ1 × FN
Ff1 = 0.226 × mgcos30
Ff1 = 0.226 × 14.29
Ff1 = 3.23N

Force Down Incline = mgsin30
Force Down Incline = 8.25N

Therefore, Tension 1 = Force Down Incline - Ff1 = 5.02N

And for m2:

Ff1 = μ1 × FN
Ff1 = 0.113 × mgcos30
Ff1 = 0.226 × 28.58
Ff1 = 3.23N

Force Down Incline = mgsin30
Force Down Incline = 16.5N

Therefore, Tension 2 = Force Down Incline - Ff2 = 13.27NFinally, Total Tension = Tension 2 - Tension 1 = 8.25N

There are no answers for this question, so I came on here hoping that someone may be able to correct me if I have done something wrong, or possibly verify my answer.

Any help greatly appreciated!

Thanks :)
 
Physics news on Phys.org
What is the tension in the rod?
Tension 1= Tensiion 2
 
azizlwl said:
What is the tension in the rod?
Tension 1= Tensiion 2

What do you mean sorry?
 
If you hang an object of mass m by a massless rod , what is the tension on the rod?
 
azizlwl said:
If you hang an object of mass m by a massless rod , what is the tension on the rod?

That is my question haha.
 
The upper mass will pull up the lower mass.
The reaction of this the lower will pull the upper mass too.
So action and reaction are the same tension on the rod.
Use fbd for the lower mass and the upper mass to find the tension where tension pull are the same, only different direction.
 

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