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TEST OUTLINE:

 

          -vibrations and waves:            definition, three types

          -calculation: universal wave equation

          -terms and calculations: frequency, period

          -terms: rarefaction, compression, trough, crest, wavelength, torsional, longitudinal, transverse

          -standing waves, amplitude,

          -reflection of waves / pulses: free end reflection and fixed end reflection

          -mechanical resonance: defined, how it works

          -Principle of Superposition: interference of pulses travelling down a medium

          -pitch, sound intensity, hearing loss what happens to cause it

          -calculation: how much does the sound intensity change when you go from 10 dB to 50 dB. (Answer: 10,000 x)

          -calculation of speed of sound in air at various temperatures

          -deciBel scale, what are the approximate dangerous sound intensities

          -how the ear, human voice works

          -other applications of sound: ultrasound for medical imaging, treatment,

          -turbulent and laminar flow

          -Doppler effect: explanation and calculation

          -sonic booms

          -beat frequency: calculation

          -resonance in closed air columns and open air columns: concept and calculation


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Here is a typical test from a previous year. For your test on Friday, March 28th, there will be NO multiple choice questions. Answers have not been provided for this review.

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SPH 3U                                       TEST: WAVES and SOUND 

name:______________

1.         Match the terms with the definitions, below:

17 marks

A.        cycle

B.        node

C.        ultrasonic

D.        infrasonic

E.        loop

F.        resonance

G.        Doppler effect

H.        rarefaction

I.         reflection

J.         refraction

K.        longitudinal

L.        transverse

M.       torsional

N.        meters

O.        compression


P.        wavelength

Q.        period

R.        pitch

S.        loudness

T.        decibel

U.        anvil & hammer

V.        cochlea

W.       amplitude

X.        ear drum

Y.        interference

Z.        crest

AA.     trough

BB.     Hertz (Hz)

CC.     frequency

DD.     Huygen’s Principle 


_____when sound waves strike an object and bounce back

_____these ear “bones”transmit vibrations.

_____region within a wave where particles of air are closer than normal

_____length of time for one complete cycle of a vibration to occur

_____area of permanent destructive interference in a standing wave

_____number of cycles/second is the ___________

_____this occurs when two or more waves act simultaneously on the same particle of a medium

_____common term describing frequency of a sound

_____ this describes the creation of secondary wave fronts by points of along the primary wave

_____ the collapse of the Tacoma Narrows Bridge (1941) was a _________ type of wave.

_____distance in either direction from the rest position to the maximum displacement

_____the lowest point on a water wave

_____this occurs when a stationary listener hears the varying frequency of a sound generated on a moving object as it passes.

_____amplification of sound when a permanent standing wave is created

_____sounds with frequencies lower than which can be heard by the human ear

_____sound is a ______________ type of wave.

_____unit of sound intensity or loudness

 

 

2.         An upright wave pulse travels from a spring where its speed is 20 cm/s into a second spring where its speed is 10 cm/s.

 

            (A)      What will happen to its frequency and wavelength in the second spring

2 marks

 

 

 

            (B)      Sketch (as accurately as possible) what the two springs will look like seconds after the incident pulse has reached the interface between the two boundaries.

3 marks

 

                                    Sketch not shown: two positive (+) pulses approaching each other

 

 

 

3.         Sketch the resulting waves when a straight wave front strikes a barrier set at a 45o angle. Name the two principles illustrated here.

3 marks

 

 

 

 

 

 

 

 

 

 

4.         Someone is watch his neighbour chopping wood from across a lake. As he watches, he notices a time delay of 2.1 s between the time the axe hits the wood and the time he hears the sound. The air temperature is 8.0 o C. What is the distance he is away from his neighbour? Assume the speed of light is infinitely quick.

3 marks

 

 

 

 

 

 

 

 

 

 

5.         A student construction a homemade flute. She tests the flute at 22o C using different lengths and collects data relating to resonant length and frequency.

            .a)       Complete column 3 of the table with an appropriate fraction.

 

length at which resonance occurs (m)

frequency of sound (Hz)

Resonance length as a fraction of wavelength

0.39

440

 

0.67

512

 

0.88

584

 

1 mark

            .b)       Is her instrument an open or closed column? Explain your answer.

2 marks

 

 

 

6.         Does sound travel faster in a solid or in a gas? Explain your answer with “sufficient detail”, considering the 4 marks allotted to the question.

 4 marks

 

 

 

7.         Water waves in a ripple tank are 2.6 cm long. The wave generator sends out 60 wave crests in 42 seconds.

            1.         determine the frequency of the wave

1 mark

 

 

            2.         determine the speed of the wave

1 mark

 

 

8.         Canadian Forces jets flying from Cold Lake, Alberta are restricted from flying at supersonic speeds over certain areas. Write a thoughtful, organized, detailed and knowledgeable 10 mark (very short) essay addressing the following points:

8 marks

-Discuss and explain the specific effects which occur when planes flying at slower speeds suddenly begin to travel at speeds greater than the speed of sound.

-Discuss the possible effects on wildlife and human settlements subjected to regular low level supersonic air traffic.

-Explain why high altitude supersonic flights affect greater areas, but have a diminished impact on the ground.

 

                                    

 

9.         Two pulses move towards each other as shown. Sketch the resultant pulse at the moment the two pulses’ centre lines are lined up.

1 mark

 

                                    Insert diagram: superposition

 

 

 

 

 

10.       (A)      In a list, describe how sound is transmitted through the middle and inner ear. Be sure to also list the function of each part in your answer.

4 marks

 

 

 

 

            2.         Describe what happens when the human ear is damaged by a too loud sound. Include in your answer the approximate value for the TLV-ceiling sound intensity, and explain the term.

4 marks

 

 

 

 

 

 

 

 

 

TEST TOTAL: 55 MARKS