Plucking a string provides it with an initial energy displacement (potential energy).
The shape of the string before its release completely defines the harmonic signature of the resulting motion.
A string plucked at 1/nth the distance from one end will not have energy at the nth partial and its integer multiples.
The strength of excitation of the nth vibrational mode is inversely proportional to the square of the mode number.
The Struck String:
A struck string is given an initial velocity distribution (kinetic energy).
A string struck at 1/nth the distance from one end will not have energy at the nth partial and its integer multiples.
The harmonic amplitudes in the vibration spectrum of a struck string fall off less rapidly with frequency than those of plucked strings.
Light “hammers” (mass much less than the mass of the string) result in little spectral drop-off with frequency. Heavier hammers produce a drop-off roughly proportional to the inverse of the mode number.
“Stick-slip” mechanism: During the greater part of each period, the string is “stuck” to the bow and is carried with it in its motion. Then the string suddenly detaches itself and moves rapidly backward until it is caught again by the moving bow.
Beginning and end of the slipping are triggered by the arrival of the propagating bend or “kink”.
The string's vertical motion at any one point is given by a sawtooth pattern.
Round trip time depends only on the string length and the wave velocity.
Bowing near the string end requires greater force and produces a louder, brighter sound than bowing farther from the end.
Amplitude of vibration can be increased either by increasing the bow speed or by bowing closer to the bridge.