Coefficent of kinetic friction

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SUMMARY

The discussion centers on calculating the minimum coefficient of kinetic friction required to stop a train that is skidding into buffers at a station. The problem involves a train of mass m with an initial speed v, encountering buffers that compress a spring with a spring constant k. The maximum compression of the spring is given as 1 meter, and the gravitational field strength is denoted as g. The Work Energy Theorem is applied, leading to the equation μmg - 1/2kx² = -1/2mv², where μ represents the coefficient of kinetic friction.

PREREQUISITES
  • Understanding of the Work Energy Theorem
  • Knowledge of Hooke's Law and spring constants
  • Familiarity with kinetic energy equations
  • Basic concepts of friction and gravitational force
NEXT STEPS
  • Study the derivation of the Work Energy Theorem in physics
  • Explore Hooke's Law applications in real-world scenarios
  • Learn how to calculate coefficients of friction in various contexts
  • Investigate the dynamics of trains and braking systems
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Students in physics, particularly those studying mechanics, engineers involved in transportation safety, and anyone interested in the principles of motion and friction.

spiegalr
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Homework Statement


A train, of mass m, comes into a station traveling slightly too fast to stop in time before it hits the buffers at the end of the track. The buffers are effectively metal plates attached to a spring which obeys Hooke's law with a spring constant k. The trains wheels lock and it skids along the horizontal rails with sparks flying so that at the point that the train first touches the buffers it has a speed v. If the maximum compression of the spring in the buffers is 1m what is the minimum coefficient of kinetic friction between the locked wheels of the train and the rails for the buffers to be able to stop it given that the gravitational field is g?

Homework Equations


W = 1/2kx^2
KE = 1/2mv^2
W = [tex]\mu[/tex]mgh

The Attempt at a Solution


I've tried using the Work Energy Theorem like so:
[tex]\mu[/tex]mgh - 1/2kx^2 = 0 - 1/2mv^2
But I have no idea what directions to take, or even if I'm using the right formula.
Thanks!
 
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Welcome to PF!

Hi spiegalr! Welcome to PF! :wink:

Hint: what is the work done by the force of friction? :smile:
 

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