Oscillations and Waves > Instruments > Strings DCS# 3D20.20
MOTION OF BOWED STRING

APPARATUS
 
monochord with violin string 202-07-B
small horseshoe magnet 202-07-B
1 kg weight hanger 202-04-E
additional 5.5 kg weights 202-04-E
microphone preamplifier 202-06-D
10 kΩ resistor  107-resistor cabinet
1 uF capacitor 101-09-I1
storage scope 202-08-B
C clamps 202-01-E5
violin bow 202-06-B
video camera 202-09-D

DESCRIPTION
Voltage across wire vibrating in magnetic field is proportional to instantaneous velocity.  Amplifier output also integrated with RC network having RC = 0.01 s to display displacement.  Both curves are inverted, as expected, when one changes from up-bow to down-bow.
-REW
NOTES
Set-up:
 


REFERENCE

John Schelleng, Sci. Am., Jan. 1974, p.87.