Forced vibrations and resonance

Nature of science:

Risk assessment: The ideas of resonance and forced oscillation have application in many areas of engineering ranging from electrical oscillation to the safe design of civil structures. In large-scale civil structures, modelling all possible effects is essential before construction. (4.8)

• Natural frequency of vibration
• Q factor and damping
• Periodic stimulus and the driving frequency
• Resonance

Applications and skills:

• Qualitatively and quantitatively describing examples of under-, over- and critically- damped oscillations
• Graphically describing the variation of the amplitude of vibration with driving frequency of an object close to its natural frequency of vibration
• Describing the phase relationship between driving frequency and forced oscillations
• Solving problems involving Q factor
• Describing the useful and destructive effects of resonance

• Communication through radio and television signals is based on resonance of the broadcast signals

Utilization:

• Science and technology meet head-on when the real behaviour of damped oscillating systems is modelled

• Only amplitude resonance is required

Data booklet reference:

• Aim 6: experiments could include (but are not limited to): observation of sand on a vibrating surface of varying frequencies; investigation of the effect of increasing damping on an oscillating system, such as a tuning fork; observing the use of a driving frequency on forced oscillations
• Aim 7: to investigate the use of resonance in electrical circuits, atoms/molecules, or with radio/television communications is best achieved through software modelling examples