Experiment 12: Wave Motion and Resonance

Vocabulary practice flashcards covering wave motion, standing wave theory, resonance, safety rules, and experimental apparatus (stroboscope and oscilloscope) from Experiment 12.

Standing waves

Waves that occur when two identical waves travel in opposite directions in the same medium, characterized by regions of no oscillation called nodes and regions of large oscillation called anti-nodes.

Nodes

Regions along a standing wave of no oscillation, corresponding to positions of zero displacement.

Anti-nodes

Regions along a standing wave characterized by large oscillation.

Wave velocity ($v$)

The velocity of a wave along a string, given by the relationship $v = \sqrt{\frac{F}{\mu}}$, where $F$ is the tension in the string and $\mu$ is the mass per unit length.

Circularly polarised wave

A wave generated by the oscillator that behaves similarly to a plane wave and is the superposition of many plane waves of all possible orientations of the plane of vibration.

Resonance

The condition achieved when travelling waves reflect and superpose to form stable standing waves, which is identified by a stable positioning of the nodes and achieved by adjusting the string tension.

Bridge

The point directly underneath the spring balance and pulley in the experimental apparatus.

Node-to-node separation

The distance between two successive nodes in a standing wave, which is equal to half a wavelength ($\frac{\lambda}{2}$).

Mass per unit length ($\mu$)

The linear density of the string, which can be calculated using the relation $F = f^2 \lambda^2 \mu$ or by determining the slope ($\text{slope} = f^2 \mu$) of a plot of tension $F$ versus $\lambda^2$.

Stroboscope

An instrument that emits brief, very bright flashes of light at regular, adjustable intervals to make cyclic motion appear stationary.

Stroboscope frequency condition

The relation $f = n f_s$, where the vibrating string appears stationary whenever the string completes an integer number $n$ of complete revolutions between stroboscope flashes at frequency $f_s$.

Oscilloscope

A precision instrument functioning as a voltmeter that displays and analyzes voltage waveforms over time, with the vertical axis representing voltage and the horizontal axis representing time.

Horizontal controls (Oscilloscope)

Controls on an oscilloscope used to shift the waveform position horizontally and adjust the time scale (time per division).

Vertical controls (Oscilloscope)

Controls on an oscilloscope used to shift the waveform position vertically and adjust the voltage scale (volts per division).

AUTO button (Oscilloscope)

A control button on the oscilloscope used to automatically locate and display any voltage waveforms present on the screen when they are not initially visible.