3B SCIENTIFIC® PHYSICS Wellenwanne U21910

3.3 Reflection of a linear wave at a concave
mirror
• Proceed as in Experiment 1.6
• Place the obstruction with a wide slit
about 5 cm to 10 cm in front of the exciter
and parallel to the waves
• Place the biconcave body in the slit and
close the slit around it with the adjustment
plates (the body of the lens ought
to stick up out of the water)
• Make fine adjustments to the frequency
and amplitude till the "focussing effect"
is clearly visible
3.4 Reflection of a linear wave at a convex
mirror
• Proceed as in Experiment 3.3
• Replace the biconcave body with the biconvex
body
• Make fine adjustments to the frequency
and amplitude till the "dispersing effect"
is clearly visible
4. Refraction of waves
4.1 Demonstration of differing speeds of
propagation in deep water and shallow
water
• Fill the tank with water until all immersed
bodies are completely submerged
(Water about 5.5-6.0 mm
deep)
• Alter the height of the exciter (so that it
just touches the water)
• Make sure everything is nicely wetted
(add washing up liquid if necessary)
• Immerse the rectangular block (About 5
cm from the exciter with the narrow
end parallel to the waves)
• Proceed as in Experiment 1.6
Result: the waves travel more slowly where the
water is shallower
Shallow water is a denser medium
Refractive index n > 1
6