Does Normal Force Do Work in Vertical Motion?

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Homework Help Overview

The discussion revolves around a physics problem involving the forces acting on a 2 kg object being pulled upward with an acceleration of 2.2 m/s². Participants are tasked with calculating the work done by various forces, including the applied force, normal force, and gravitational force, while also considering the net work done on the object.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts to calculate the work done by each force and expresses confusion about the inclusion of the normal force in vertical motion. Some participants question the necessity of the normal force in this context, while others explore energy conservation principles.

Discussion Status

The discussion is ongoing, with participants seeking clarification on the role of the normal force and the application of energy conservation equations. There is a mix of interpretations regarding the forces involved and how they contribute to the work done.

Contextual Notes

Participants note the complexity of calculating net work when multiple forces are acting, and there is uncertainty about the relevance of the normal force in this upward motion scenario. The original poster also mentions time constraints affecting their ability to provide more details.

Vontox7
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Hello,
I have become very confused after i tried to solve this question.
A rope pulls a 2 kg object straight up, accelerating it from rest at 2.2 m/s^2 for 3 seconds.
they want the work done by each force acting on it.
Ok i found the displacement as 9.9 m up. Then i found out that the applied force does 43.56 J and that Fn does 150.678 J and gravity does 194.238 J .

Then they ask for the total mechanical work done. I just added the works and got -.678 . Then they ask for the net force which is 4.4 N up and work done by the net force which is 43.56 J.

I am confused about finding the net work when fg,fn, fapp are involved what am doing wrong. Also when solving other questions do i include fn and fg when the displacement is vertical?

Please help and thank you. i would add more detail but i got no time to study.
 
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E initial = E final

0 = - mg*X + F*X + mV^2/2

You can figure out all three.

?
 
I am sorry but i don't understand your formula. yes, i know that initial potential and kinetic energy equal the final but the next line i don't understand what it is nor how it can help.
 
Vontox7 said:
Hello,
I have become very confused after i tried to solve this question.
A rope pulls a 2 kg object straight up, accelerating it from rest at 2.2 m/s^2 for 3 seconds.
they want the work done by each force acting on it.
Ok i found the displacement as 9.9 m up. Then i found out that the applied force does 43.56 J and that Fn does 150.678 J and gravity does 194.238 J .

Then they ask for the total mechanical work done. I just added the works and got -.678 . Then they ask for the net force which is 4.4 N up and work done by the net force which is 43.56 J.

I am confused about finding the net work when fg,fn, fapp are involved what am doing wrong. Also when solving other questions do i include fn and fg when the displacement is vertical?

Please help and thank you. i would add more detail but i got no time to study.
What is Fn, a normal force? Are you sure there is a normal force acting on the object while it is accelerating upward?
 

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