Can't find mistake on Spring/block Energy problem

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SUMMARY

The discussion centers on a physics problem involving a 1.93 kg block on a rough incline at a 38.2-degree angle, connected to a spring with a spring constant of 90 N/m. The block moves 10.9 cm down the incline before coming to rest, and the user attempts to calculate the coefficient of kinetic friction (μk) using the work-energy principle. The user initially calculated μk as approximately 0.4439 but received feedback indicating the answer was incorrect, prompting a request for assistance in identifying the mistake in their calculations.

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  • Understanding of Newton's laws of motion
  • Familiarity with the work-energy principle
  • Knowledge of spring mechanics, specifically Hooke's Law
  • Basic trigonometry, particularly sine and cosine functions
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  • Review the work-energy principle in the context of inclined planes
  • Study the application of Hooke's Law in spring systems
  • Learn how to calculate the coefficient of friction using energy methods
  • Explore problem-solving techniques for dynamics involving friction and springs
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Students studying physics, particularly those focusing on mechanics, as well as educators looking for examples of problem-solving in dynamics involving friction and spring systems.

falco451
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Homework Statement



A 1.93 kg block situated on a rough incline with 38.2 angle is connected to a spring of negligible mass having a spring constant of 90 N/m.
The block is released from rest when the spring is unstretched, and the pulley is frictionless. The block moves 10.9 cm down the incline before coming to rest.

Homework Equations



W = (fk cos 180)
x= -[tex]\mu[/tex]k(mg cos theta)
Wnc = ( KE + PEg + PE s)f - (KE + PEg + PEs)i


The Attempt at a Solution



I used the equations and combined them to get:
-[tex]\mu[/tex]k(18.194N cos 38.2) (.109) = 0 + (18.194)(-.109sin 38.2)
+ .5(90 N/m)(.109^2)

For my answer I got [tex]\mu[/tex]k = .4438645593
It says that my answer is wrong and I can't find what I did wrong. I recalculated several times and still got the same answer. Can you help me? Thank you!
 
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I retried calculating, and I got a different answer that was close to the one I had already gotten, but it was still wrong.
 

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