Error in Natural Frequency (Lab)

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SUMMARY

The discussion focuses on calculating the error in the period of a resonant frequency experiment using the formula $$T = 2π\sqrt{m/k}$$. The user seeks clarification on error propagation, specifically how to apply the equations for error in measurements of mass (m) and spring constant (k). The correct approach involves using the error propagation formulas, leading to the final expression for the error in the period, $$ΔT = π\sqrt{(Δm)^2/(mk)+(m(Δk)^2)/k^3}$$. This confirms the user's calculations and emphasizes the importance of understanding error propagation in experimental physics.

PREREQUISITES
  • Understanding of resonant frequency and its mathematical representation.
  • Familiarity with error propagation techniques in physics.
  • Knowledge of basic calculus, particularly derivatives and powers.
  • Experience with measurement uncertainties and their calculations.
NEXT STEPS
  • Study advanced error propagation methods in experimental physics.
  • Learn about the significance of resonant frequency in mechanical systems.
  • Explore the application of error analysis in real-world experiments.
  • Investigate the impact of measurement precision on experimental results.
USEFUL FOR

Students in physics labs, educators teaching experimental methods, and researchers conducting experiments involving resonant frequencies and error analysis.

Afterthought
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So I just did a lab on resonant frequency, and have to find the error of the period: $$T = 2π\sqrt{m/k}$$
m and k were measured with an error of Δm and Δk. My teacher didn't explain well how to do errors, so I just want to know if I did this right.

Prorogation of Error equations:
$$y=x^n ⇒ Δy=nx^{n-1}Δx$$ $$y=x_1/x_2 ⇒ Δy=y\sqrt{(Δx_1/x_1)^2+(Δx_2/x_2)^2}$$

Attempt at solution:
$$Δ(m/k)^{0.5}=0.5(m/k)^{-0.5}Δ(m/k)$$ $$Δ(m/k)=(m/k)\sqrt{(Δm/m)^2+(Δk/k)^2}$$ $$ Therefore, ΔT = 2π * 0.5(m/k)^{-0.5}(m/k)\sqrt{(Δm/m)^2+(Δk/k)^2}=π\sqrt{(Δm)^2/(mk)+(m(Δk)^2)/k^3}$$
 
Last edited:
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Right.
The expression gets easier if you write down ##\frac{\Delta T}{T}##.
 
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