3B SCIENTIFIC® PHYSICS Wellenwanne U21910

Ripple tank experiments
1. Generation of waves
1.1 Creating ripples
1.2 Superposition of two ripple sources
1.3 Generating a wake
1.4 Superposition of two wakes
1.5 Circular wavefronts
1.6 Linear wavefronts
6. Superposition (interference) of coherent
waves
6.1 Superposition of multiple circular waves
6.2 Interference at a double slit and a triple
slit
7. Doppler effect
7.1 Exciter speeds slower than the wave
propagation speed (u < v)
2. Huygen's principle
2.1 Straight wavefronts encountering a narrow
slit
2.2 Circular wavefronts encountering a narrow
slit
2.3 How a block resembles a point-shaped
source (wave exciter)
3. Reflection of waves
3.1 Reflection of a linear wave at a plane
wall
3.2 Reflection of a circular wave at a plane
wall
3.3 Reflection of a linear wave at a concave
mirror
3.4 Reflection of a linear wave at a convex
mirror
4. Refraction of waves
4.1 Demonstration of differing speeds of propagation
in deep water and shallow water
4.2 Refraction of a linear wave at a rectangular
glass plate
4.3 Refraction of a linear wave at a convex
lens
4.4 Refraction of a circular wave at a convex
lens
4.5 Refraction of a linear wave at a concave
lens
4.6 Refraction of a linear wave at a combination
of lenses
4.7 Refraction of a linear wave at a prism
General notes on ripple tank experiments
The ripple tank should be set up as specified
in the instruction manual. The instructions in
the manual should be observed in the course
of all experiments.
Since the peaks of waves in the tank act like
convex lenses, they appear as bright lines
when the tank is projected onto a screen. The
troughs between them act like concave lenses
and appear as darker lines.
When vibrator and stroboscope frequencies
are synchronised, static wave projections can
be achieved.
Good results are obtained at an exciter frequency
of about 20 Hz where the exciter is
finely adjusted for amplitude (the wave peaks
are then about 1 cm apart).
The stroboscope should be switched on for all
the experiments.
For experiments using the vibrator, it is always
possible to use the linear wave exciter
since the dippers can be adjusted upwards
out of the water.
5. Refraction of linear waves
5.1 Refraction at an edge
5.2 Refraction at a single slit (wavelengths
greater than/smaller than the width of
the slit)
5.3 Refraction at a single slit (width approx.
10 cm)
5.4 Refraction at an obstruction (width approx.
10 cm)
To reduce surface, a few drops of washing up
liquid should be added to the water in the
tank.
For refraction experiments, the water level
should be about 1 mm above the top of the
immersed bodies so that relative large refractive
indices can be observed.
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