Lamalam
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During forced oscillation,
-->Amplitude of oscillation - gradually increase (energy transfer is cumulative), why energy is cumlative, are there any other examples proving that energy is cumulative?

-->At equilibrium,
- rate of energy from driving force = rate of energy dissipated by damping force, so amplitude becomes constant

Actually does damping means friction, and in most cases, is air resistance damping?


thank you!!!
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uberteknik
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(Original post by Lamalam)
During forced oscillation,
-->Amplitude of oscillation - gradually increase (energy transfer is cumulative), why energy is cumlative, are there any other examples proving that energy is cumulative?
Forced oscillation means external energy is continually added to the system at every period. Because of the energy conservation laws, if the added energy is not lost, then the kinetic and potential energy of the system must be increasing. i.e. the incoming energy is stored as an increased amplitude of oscillation.

Think of a child on a swing getting higher and higher at every new push.

(Original post by Lamalam)
-->At equilibrium,
- rate of energy from driving force = rate of energy dissipated by damping force, so amplitude becomes constant

Actually does damping means friction, and in most cases, is air resistance damping?
Precisely. In all cases, air resistance is damping.

Damping is often used (but not exclusively) to describe deliberate and controlled friction losses. i.e. the shock absorbers of a car suspension system uses a viscous fluid to apply controlled damping to the road spring supporting the vehicle (4 of them). Road bumps quickly compress the spring (stored energy) which then releases that energy via the damping fluid and thus it dissipates over a longer time before the spring returns to the rest equilibrium postion. The shock absorber suppresses spring oscillation and dissipates energy in a controlled manner to produce a smooth ride.
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Lamalam
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(Original post by uberteknik)
Forced oscillation means external energy is continually added to the system at every period. Because of the energy conservation laws, if the added energy is not lost, then the kinetic and potential energy of the system must be increasing. i.e. the incoming energy is stored as an increased amplitude of oscillation.

Think of a child on a swing getting higher and higher at every new push.

Precisely. In all cases, air resistance is damping.

Damping is often used (but not exclusively) to describe deliberate and controlled friction losses. i.e. the shock absorbers of a car suspension system uses a viscous fluid to apply controlled damping to the road spring supporting the vehicle (4 of them). Road bumps quickly compress the spring (stored energy) which then releases that energy via the damping fluid and thus it dissipates over a longer time before the spring returns to the rest equilibrium postion. The shock absorber suppresses spring oscillation and dissipates energy in a controlled manner to produce a smooth ride.
thank you very much!! completely understand this !
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