waves

1. Reflection and
Transmission of Mechanical
Waves
demoweb.physics.ucla.edu

2. True/False Question
When a pulse is reflected from a
fixed end it is not inverted:
TRUE
FALSE

3. CORRECT!
When a pulse is reflected from a fixed end
it is inverted!
As the pulse reaches the end, the string
exerts an upward force on the rigid support
and the rigid support exerts an equal and
opposite force on the string
http://astarmathsandphysics.com/a-level-physics-notes/waves-and-oscillations/a-level-physics-notes-reflection-of-waves-html-
m5bffd405.gif

4. INCORRECT :(
When a pulse is reflected from a fixed end
it is inverted!
As the pulse reaches the end, the string
exerts an upward force on the rigid support
and the rigid support exerts an equal and
opposite force on the string
http://astarmathsandphysics.com/a-level-physics-notes/waves-and-oscillations/a-level-physics-notes-reflection-of-waves-html-
m5bffd405.gif

5. True/False Question
The reflected pulse is inverted.
TRUE
FALSE

6. CORRECT!
The reflected pulse is inverted.
The blue string serves as a fixed end and
thus the reflected pulse is inverted.
http://www.physicsclassroom.com/Class/waves/u10l3a6.gif

7. INCORRECT :(
The reflected pulse is inverted.
The blue string serves as a fixed end and
thus the reflected pulse is inverted.
http://www.physicsclassroom.com/Class/waves/u10l3a6.gif

8. True/False Question
The transmitted pulse is inverted
and the reflected pulse is not
inverted.
TRUE
FALSE

9. CORRECT!
Both the transmitted pulse and the reflected
pulse are not inverted.
The red string serves as a free end and thus,
the reflected pulse is not inverted.
http://www.physicsclassroom.com/Class/waves/u10l3a7.gif

10. INCORRECT :(
Both the transmitted pulse and the reflected
pulse are not inverted.
The red string serves as a free end and thus,
the reflected pulse is not inverted.
http://www.physicsclassroom.com/Class/waves/u10l3a7.gif

11. Question
How did the pulse look like before it
was reflected?

12. CORRECT!
This is a fixed end so the pulse is inverted.

13. INCORRECT :(
This is a fixed end so the pulse is inverted.

14. True/False Question
Match the incident pulse with the
correct reflected pulse (free end).
A
B
C
D
http://dev.physicslab.org/Document.aspx?doctype=5&filename=WavesSound_FixedFreeReflections.xml

15. CORRECT!
The pulse is not inverted because it is a free end.

16. INCORRECT :(
The pulse is not inverted because it is a free end.

17. Important Concepts
Fixed end -> pulse is inverted
Free end -> pulse is not inverted
When pulse is traveling to a different
string which is more dense, the pulse is
inverted
When pulse is traveling to a different
string which is less dense, the pulse is not
inverted

18. Important Concepts
http://www1.union.edu/newmanj/Physics100/Light%20as%20a%20Wave/outofphasewaves.gif
http://www.schoolphysics.co.uk/age16-19/Wave%20properties/Wave%20properties/text/Phase_change/images/3.png