Key terms

• Critical damping

  Where the oscillations stop and return to equilibrium in the quickest possible time
• Damping

  When the energy in a SHM system is not kept as KE or PE and the total energy is no longer constant, all real systems experience some damping from friction or air resistance
• Free vibrations

  When a system oscillates without any driving force
• Force vibration

  When a systems oscillations are forced to vibrate by an external driving force
• Light damping

  Where the oscillations amplitudes reduce slowly, friction and air resistance cause light damping
• Natural frequency

  The frequency at which a system naturally vibrates, a free vibration will be at natural frequency
• Overdamping

  When the damping is greater than critical damping, it stops the oscillations but the system takes longer to return to equilibrium position quicker than a critically damped system
• Pendulum oscillator

  A mass on a string that oscillates with simple harmonic motion from side to side, the time period is independent of the objects mass and the initial displacement
• Resonance

  When the driving force is at natural frequency of a system causing maximal energy transfer with the amplitude of the oscillation at its maximum. The driving force is Pi/2 radians ahead of the phase of the oscillations
• Simple harmonic motion

  A mechanical process where the force on an object is proportional to the negative of the displacement from equilibrium. This means that there is always a resorting force pointing towards the equilibrium which is proportional to the extension. The resulting motion is oscillatory about this equilibrium position
• Spring oscillator

  A mass on a spring that oscillates with simple harmonic motion up and down. The time period is independent of gravitational field strength and the initial displacement