Oscillations
and Waves > Instruments > Resonance in Solids
DCS# 3D40.50x
STANDING WAVES
IN
A
COFFEE MUG
APPARATUS
coffee
mug
202-05-C
spoon
202-05-C
DESCRIPTION
Tap the mug with a spoon at 45
degree intervals
around the rim to hear alternating higher and lower
frequencies.
Tapping the mug excites circular
standing
waves around the rim whose nodes are 90 degrees apart.
If the mug
is tapped so that the handle is at an antinode, the resonant
frequency
is lower than if the handle is at a node because of the
greater
vibrating
mass.
