Damping

• What happens to all oscillators in practice?

  They eventually stop oscillating
• What causes the amplitudes of oscillators to decrease?

  Resistive forces like friction or air resistance
• What are damped oscillations?

  Oscillations affected by resistive forces
• How is damping defined?

  Reduction in energy and amplitude due to resistive forces
• What happens to an oscillator during damping?

  It comes to rest at the equilibrium position
• Does the frequency of damped oscillations change as amplitude decreases?

  No, it remains constant
• What causes damping on a mass on a spring?

  A resistive force acting opposite to motion

  
• What are the three types of damping?

  Light damping, critical damping, heavy damping
• What occurs during light damping?

  • Amplitude does not decrease linearly
  • Decays exponentially with time
  • Oscillates with gradually decreasing amplitude
• How does a lightly damped oscillator behave when displaced?

  It oscillates with gradually decreasing amplitude
• What does a graph for a lightly damped system show?

  Oscillations decreasing exponentially

  
• What are key features of a displacement-time graph for a lightly damped system?

  Decreasing amplitude, constant frequency, sine/cosine curve

  
• What happens in critical damping?

  • Returns to rest in shortest time
  • No oscillations occur
  • Example: car suspension systems
• What does the graph for a critically damped system show?

  No oscillations, quick return to zero

  
• What are key features of a displacement-time graph for a critically damped system?

  Fast decreasing gradient, no oscillations

  
• What occurs during heavy damping?

  • Takes a long time to return to equilibrium
  • No oscillations occur
  • Example: door dampers
• What does a heavy damping curve show?

  No oscillations, slow return to zero
• What are key features of a displacement-time graph for a heavily damped system?

  Slow decreasing gradient, no oscillations

  
• What damping should be applied to a mechanical weighing scale?

  • Critical damping is ideal
  • Settles quickly without oscillating
• Why is critical damping preferred for a weighing scale?

  It allows the needle to settle quickly
• What is the difference between resistive force and restoring force?

  • Resistive force opposes motion and causes damping
  • Restoring force brings oscillator back to equilibrium
• What is the role of resistive force in oscillation?

  It opposes the motion of the oscillator
• What is the role of restoring force in oscillation?

  It brings the oscillator back to equilibrium