Friction force calculation of syringe plunger

AI Thread Summary
The discussion focuses on calculating the static friction of a syringe plunger's rubber seal. The user measured the push and pull forces required to move the plunger, with values of 0.625 and 0.677777778, respectively. Initially unsure how to derive the coefficient of friction from these measurements, the user later realized that a free body diagram allowed for the use of the measured forces directly. Another participant questioned the necessity of the coefficient if the friction force was already known. The conversation highlights the importance of understanding friction in mechanical systems.
ktm_rider
Messages
3
Reaction score
0
Hi all,

This is my first post here. I finally decided to sign up after using the site for many years.

I am working on a project involving a syringe mechanism. I am using a stock 6ml syringe. I'm trying to calculate the static friction of the rubber seal.

I have measured both the pull and push forces required to move the plunger, but am blanking on how to actually get the coefficient of friction from those numbers.

The pushing force is:0.625
The pulling force is: 0.677777778

Thank you for all the help!

Tyler
 
Physics news on Phys.org
I think you would have to know the force being applied to force the two surfaces together, not sliding back and forth over each other.
 
Hm, okay. Any suggestions on the best way to go about that?

Thank you
 
I think i figured it out.

After drawing out the free body diagram, I can use the actual forces i measured without having to solve for the coefficient of friction.

Thank you for your help Drakkith
 
Why do you need the coefficient if you have the friction force?

(edit: you figured it out while I was posting.)
 

Thread 'Is calling fictitious forces "not real" just about terminology?'

Hi there, im studying nanoscience at the university in Basel. Today I looked at the topic of intertial and non-inertial reference frames and the existence of fictitious forces. I understand that you call forces real in physics if they appear in interplay. Meaning that a force is real when there is the "actio" partner to the "reactio" partner. If this condition is not satisfied the force is not real. I also understand that if you specifically look at non-inertial reference frames you can...
View full post »

Thread 'Inclined treadmills and Galilean Invariance'

This has been discussed many times on PF, and will likely come up again, so the video might come handy. Previous threads: https://www.physicsforums.com/threads/is-a-treadmill-incline-just-a-marketing-gimmick.937725/ https://www.physicsforums.com/threads/work-done-running-on-an-inclined-treadmill.927825/ https://www.physicsforums.com/threads/how-do-we-calculate-the-energy-we-used-to-do-something.1052162/
View full post »

Thread 'Derivation of Hamilton's Principle: Questions'

I have recently been really interested in the derivation of Hamiltons Principle. On my research I found that with the term ##m \cdot \frac{d}{dt} (\frac{dr}{dt} \cdot \delta r) = 0## (1) one may derivate ##\delta \int (T - V) dt = 0## (2). The derivation itself I understood quiet good, but what I don't understand is where the equation (1) came from, because in my research it was just given and not derived from anywhere. Does anybody know where (1) comes from or why from it the...
View full post »

Similar threads

Calculating Friction Force for a Waterproof Seal in a Syringe Setup
Replies
2
Views
4K
The Relationship Between Volume and Force in a Sealed Syringe
Replies
9
Views
9K
I If frictional force in system is <= us*N then there is no slipping
Replies
7
Views
2K
Damping and friction in syringe equation of motion
Replies
4
Views
2K
Fluid Dynamics - Pressure at the end of a syringe
Replies
5
Views
15K
I Modeling Coulomb Friction for a Moving Point Mass in a Circular Bowl
Replies
20
Views
1K
Friction coefficient and the force on a syringe plunger
Replies
6
Views
3K
I Torque required from powered roller to rotate cylinder
Replies
19
Views
2K
B Questions about momentum and force as well as normal force/friction
Replies
35
Views
4K
Calculating Force Needed to Pull Plunger in Standard Syringe
Replies
10
Views
19K

Hot Threads

Recent Insights

Back
Top