resonansi

Resonansi, known in Indonesian as resonansi, is the tendency of a system to respond with a large amplitude to a periodic input when the input frequency matches or is close to the system's natural frequency. The phenomenon occurs across physics, engineering, acoustics, and many natural and designed systems, and it is strongly influenced by damping, which dissipates energy.

When a periodic force drives a system, energy is transferred most efficiently near the natural frequency. This yields a pronounced peak in the response amplitude as a function of driving frequency. Systems with low damping show sharp, high peaks (high quality factor, Q); more heavily damped systems display broader, lower peaks.

Mathematically, many resonant phenomena are modeled by a driven damped harmonic oscillator: m x'' + c x' + k x = F cos(ω t). The natural frequency is ω0 = sqrt(k/m) and the damping ratio is ζ = c/(2 sqrt(k m)). The steady-state amplitude is A(ω) = (F/m) / sqrt((ω0^2 − ω^2)^2 + (2 ζ ω0 ω)^2). The resonance frequency lies near ω0, shifted downward by damping to ωr = ω0 sqrt(1 − 2 ζ^2) for ζ < 1/√2.

Common contexts include musical instruments and tuning forks, electrical filters and RLC circuits, and mechanical or structural systems where resonance can be either exploited or mitigated. Designers employ damping, stiffness changes, or isolation to prevent damaging resonant responses in buildings, bridges, and machinery.

Resonansi is a fundamental concept used to explain why objects amplify certain frequencies and why careful design is needed to control responses in real-world systems.

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