Summary

• The wave equation
• String waves
• Wave interference

Bonus question Ch.15


• Written Quiz Ch.15




• Standing waves
• Formation by reflection applet
  
another animation
• string fixed at both ends


• chart of harmonics applet
• video
Example #1
Example #2
Example #3








• Standing waves & musical instruments
• Air column resonance animation
• organ pipes applet
• flame pipe video
Example #4
Example #6
Example #7
Example #8







• Interactive Example Air column resonances

PSE10e QQ 15.4
An object of mass m on a frictionless spring oscillates with period T₁. The object is removed and replaced with an object of mass 2m. When the new object is set into oscillation, its period T₂ is


Answer



















sj6 18.25a
What happens to the fundamental frequency of a string fixed at both ends if the length of the string is doubled? It
A. doubles.
B. stays same.
C. is cut to 1/2
D. is cut to 1/4
Answer



















sj6 18.25b
What happens to the fundamental frequency of a string fixed at both ends if the mass/length is doubled? It
A. doubles.
B. stays same.
C. is cut to 1/2
D. is cut to 1/√2
Answer



















sj6 18.25c
What happens to the fundamental frequency of a string fixed at both ends if the tension in the string is doubled? It
A. doubles
B. increases by √2
C. is cut to 1/2
D. is cut to 1/√2
Answer



















kw4
An organ pipe that is open at each end is 34.3 cm long. What is its fundamental frequency? The speed of sound is 343 m/s.
A. 136 Hz
B. 250 Hz
C. 343 Hz
D. 500 Hz
Answer



















PoP5 14.51
A seiche in a 9.15-m-long pond travels from one end to the other in 2.50 s. What driving frequency during an earthquake would produce a standing wave with antinodes at each end of the pond and a node in the middle?
A. 2.50 Hz
B. 5.00 Hz
C. 22.9 Hz
D. 0.200 Hz

Answer



















pse6 18.47
When a metal pipe is cut into two pieces, f₁ is 256 Hz in one and 440 Hz in the other. What was f₁ for the original length of pipe?
A. 162 Hz
B. 184 Hz
C. 256 Hz
D. 696 Hz
Answer



















PoP5 14.41
A flute plays an 880-Hz note at 20.0°C. What frequency does it play at −5.00°C?
A. 880 Hz
B. 855 Hz
C. 842 Hz
D. 817 Hz
Answer







































answer

C. square root of 2 times T₁
The period is proportional to the square root of the mass.



















answer

C. is cut to 1/2




















answer

D. is cut to 1/√2




















answer

B. increases by √2




















answer

D. 500 Hz




















answer

D. 0.200 Hz




















answer

A. 162 Hz




















answer

C. 842 Hz