1. Oct 27, 2009

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.

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Oct 27, 2009

### PhanthomJay

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.

3. Oct 27, 2009

4. Oct 27, 2009

### PhanthomJay

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.

5. Oct 27, 2009

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 dont know how to apply the law. :(

6. Oct 27, 2009

### Jasso

Think about what do you know about the object. What is it doing? Why is it doing that?

7. Oct 27, 2009

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.

8. Oct 27, 2009

### Jasso

Sounds good to me.

9. Oct 27, 2009

I am hopeless after that what do I do?

10. Oct 27, 2009

### Jasso

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. Oct 27, 2009

Nvm found it can you check if its right http://img263.imageshack.us/img263/7161/physics.png [Broken]

Last edited by a moderator: May 4, 2017
12. Oct 27, 2009

### Jasso

Again, looks good to me. Don't forget to match your significant digits.

Quick question, what did you learn from this?

13. Oct 27, 2009