1) Reflection occurs when a wave encounters an interface between two different media, causing the wavefront to return back into its original medium. Some of the wave's energy is reflected, while some passes through. 2) Reflected and transmitted waves are generated by an incident wave striking an interface. The reflected wave returns back into the original medium, while the transmitted wave passes into the new medium. 3) The reflection and transmission of waves depends on properties of the media on both sides of the interface. A change in speed or density at the interface results in partial reflection and transmission of the incident wave.

1. Reflection and
Transmission of
Mechanical Waves
• Millathina Puji Utami
(100210102029)
• Pindah Susanti
(100210102056)

2. • Reflection is the change in direction of a
wavefront at an interface between two
different media so that the wavefront
returns into the medium from which it
originated. Common examples include the
reflection of light, sound and water waves.
• When a wave comes across a change in the
medium, an interface surface, a portion of
the wave’s energy is reflected back, and
another portion is transmitted through the
boundary.
• Reflected and transmitted waves are
generated by the incident wave.
Waves and Optics

3. x
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4. Equation for every
medium
Waves and Optics

5. transmission
reflection
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6. 1
−
Reflected and Transmitted power
2
1
+
2
Became
Waves and Optics

7. Simple example of a wave in
a tube that narrows
The reflection
coefficient is positive
so that the leading
forward compression
wavefront reflects as a
backward compression
wave and the trailing
expansion wave reflects
as an expansion wave.
The transmitted wave
must match the pressure
produced by the incident
and reflected waves at
the discontinuity in
area giving a wave of
similar form but with an
increased amplitude.
Waves and Optics

8. Simple example of a wave
in a tube that widens
The reflection
coefficient is
negative so that the
leading forward
compression wavefront
reflects as a backward
expansion wave and the
trailing expansion
wave reflects as a
compression wave. The
transmitted wave is
similar in form to the
incident wave with a
reduced amplitude
because of the
negative reflection.
Note the direction of
'circulation' in the
different waves.
Waves and Optics

9. Reflection of Transverse
Wave Pulse
• A pulse
traveling to
the right on a
heavy string
attached to a
lighter string
• Speed suddenly
increases

10. For a narrowing vessel with a
reflection coefficient R=+0.5, the
reflected wave is a compression
wave that produces flow in the
backward direction.
Waves and Optics

11. Reflection of Transverse
Wave Pulse
• A pulse
traveling to
the right on a
light string
attached to a
heavier string
• Speed suddenly
decreases

12. For an expanding vessel with a
reflection coefficient R=-0.5, the
reflected wave is an expansion
wave that produces flow in the
forward direction.
Waves and Optics

13. Thank
You