PLEASE help me solve this question about friction.

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Homework Help Overview

The original poster presents a problem involving the motion of a beer stein sliding on a bar, specifically focusing on calculating the coefficient of kinetic friction after the stein comes to rest. The context involves concepts from mechanics, including forces, motion, and friction.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss various methods for approaching the problem, including energy methods and kinematic equations. There are attempts to apply Newton's laws and to understand the relationship between forces and motion. Some participants express confusion about how to apply these concepts effectively.

Discussion Status

The discussion includes attempts to clarify the application of Newton's second law and kinematic equations. Some participants have provided guidance on considering the object's motion and forces acting on it, while others express feelings of being lost or hopeless in their understanding.

Contextual Notes

Participants note the importance of significant digits and the constraints of the forum's policy against providing direct answers. There is an ongoing exploration of foundational physics concepts relevant to the problem.

Helpplease
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Q1.A bartender slides a beer stein of mass 0.45kg horizontally along the bar with an initial speed of 3.5m/s. The stein comes to rest near the customer after sliding 2.8m. Find the coefficient of kinetic friction.


Please help me >__>
 
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Please list your relevant equations and your attempt at a solution, and someone will be glad to help. You can use energy methods or the kinematic equations and Newton's laws.
 
Thanks for replying but I have no idea how to solve it :(. I fail so much please help.
 
I can understand the difficulty you may be having with Physics, but it won't do you much good if we just crank out the method and solution for you. Besides, it is against PF policy to just hand out answers. Have you studied energy methods or at least studied the basic kinematic motion equations, and Newton's 2nd law? They are key to getting a grip on the physics of objects in rest or in motion.
 
From what I know Newton sceond law says when forces are unbalanced a object is accelerating. Also acceleration is directly proportional to force and inversely proportional to mass.Other than that I feel lost in that problem I don't know how to apply the law. :(
 
Helpplease said:
Other than that I feel lost in that problem I don't know how to apply the law. :(

Think about what do you know about the object. What is it doing? Why is it doing that?
 
The best thing i could think of is this vf^2=v0^2+2ax

vf=final velocity=0m/s
v0=initial velocity=3.5m/s
a=acceleration= solve for this
x=distance=28m

To find a then multiply it by mass to find force.
 
Helpplease said:
The best thing i could think of is this vf^2=v0^2+2ax

...

To find a then multiply it by mass to find force.

Sounds good to me.
 
I am hopeless after that what do I do?
 
  • #10
Helpplease said:
I am hopeless after that what do I do?

Again, think about what you know about the object. What can you think of that applies to this other than Newton's second law?
 
  • #11
Nvm found it can you check if its right http://img263.imageshack.us/img263/7161/physics.png
 
Last edited by a moderator:
  • #12
Again, looks good to me. Don't forget to match your significant digits.

Quick question, what did you learn from this?
 
  • #13
To know how to apply the formula I guess.
 
  • #14
I guess it didn't come out well in text. I mostly meant that humorously.
 

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