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Ch 32: AC Circuits
Knight Calc - Physics for Scientists and Engineers 5th Edition
Knight Calc5th EditionPhysics for Scientists and EngineersISBN: 9780137344796당신이 사용하는 게 아니라요?교과서 변경
32장, 문제 69b

Prove that the energy dissipation is a maximum at ω = ω₀.

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Start by recalling the formula for the power dissipated in a driven damped harmonic oscillator. The power dissipated is proportional to the square of the amplitude of oscillation and can be expressed as: \( P(\omega) = \frac{F_0^2}{2m} \cdot \frac{\gamma \omega^2}{(\omega_0^2 - \omega^2)^2 + \gamma^2 \omega^2} \), where \( F_0 \) is the driving force amplitude, \( \omega \) is the driving angular frequency, \( \omega_0 \) is the natural angular frequency, \( \gamma \) is the damping coefficient, and \( m \) is the mass.
To find the condition for maximum energy dissipation, take the derivative of \( P(\omega) \) with respect to \( \omega \) and set it equal to zero: \( \frac{dP(\omega)}{d\omega} = 0 \). This will help identify the critical points of the power function.
Simplify the derivative \( \frac{dP(\omega)}{d\omega} \) using the quotient rule and chain rule. Focus on the denominator \( (\omega_0^2 - \omega^2)^2 + \gamma^2 \omega^2 \) and the numerator \( \gamma \omega^2 \), as these terms determine the behavior of the function.
Solve the resulting equation for \( \omega \). After simplification, you will find that the maximum power dissipation occurs when \( \omega = \omega_0 \), which is the natural angular frequency of the system.
Verify that \( \omega = \omega_0 \) corresponds to a maximum by checking the second derivative \( \frac{d^2P(\omega)}{d\omega^2} \) or analyzing the behavior of the function around \( \omega_0 \). This confirms that energy dissipation is indeed maximized at \( \omega = \omega_0 \).

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주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Energy Dissipation

Energy dissipation refers to the process by which energy is transformed from one form to another, often resulting in the loss of usable energy, typically as heat. In mechanical systems, this can occur due to friction, air resistance, or internal material resistance. Understanding how energy dissipates is crucial for analyzing system efficiency and performance.
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04:10
Intro to Energy & Types of Energy

Resonance Frequency (ω₀)

The resonance frequency, denoted as ω₀, is the frequency at which a system naturally oscillates when not subjected to external forces. At this frequency, the system can absorb maximum energy from external sources, leading to increased amplitude of oscillation. This concept is vital in understanding how systems respond to periodic driving forces and the conditions under which energy dissipation is maximized.
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05:23
Resonance in Series LRC Circuits

Damping

Damping is the effect that reduces the amplitude of oscillations in a system, often due to energy dissipation mechanisms. It plays a critical role in determining how quickly a system returns to equilibrium after being disturbed. The relationship between damping and resonance frequency is essential for analyzing energy dissipation, as maximum energy loss occurs when the driving frequency matches the system's natural frequency.
추천 영상:
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LRC Circuits