Free and Forced Oscillations

• What are free oscillations?

  Oscillations with no energy transfer to surroundings
• When do free oscillations occur?

  When an oscillating system is displaced and left
• In what environment do free oscillations typically occur?

  In a vacuum
• What is considered a free vibration in air?

  Vibrations with no external forces acting
• How is a free oscillation defined?

  Only internal forces acting, no energy input
• At what frequency does a free vibration oscillate?

  At its resonant frequency
• What is required to sustain forced oscillations?

  A periodic force must be applied
• What does the periodic force do in forced oscillations?

  Replaces energy lost in damping
• What is another name for the periodic force in forced oscillations?

  External driving force
• How are forced oscillations defined?

  Oscillations acted on by a periodic external force
• At what frequency do forced oscillations oscillate?

  At the same frequency as the external force
• Why does a child on a swing need to be pushed?

  To prevent damping from air resistance
• Is striking a tuning fork a free or forced vibration?

  Free vibration
• What happens when a glass is broken by sound?

  It vibrates at the same frequency as sound
• Is breaking a glass from sound a free or forced vibration?

  Forced vibration
• What causes the interior of a car to vibrate at high speed?

  The wheels traveling over a rough surface
• Is the vibration of a car's interior a free or forced vibration?

  Forced vibration
• What sustains the vibration in a clarinet?

  Air from the player's lungs
• Is playing the clarinet a free or forced vibration?

  Forced vibration
• What are the key differences between free and forced oscillations?

  • Free oscillations: no external forces, only internal forces, no energy input
  • Forced oscillations: external periodic force, energy input required, oscillates at external frequency
• What tips should be followed for exam answers regarding oscillations?

  • Reference internal and external forces
  • Mention energy transfers
  • Avoid vague statements