12 C Section review

Question 1

What do we call waves in matter that transmit energy through particle motion? What nonmaterial waves consist of pure energy?

Answer 1

Mechanical waves.

Electromagnetic waves.

Question 2

Sketch a single cycle of a waveform and label the parts and dimensions of the wave.

Answer 2

include: rest position (in the middle), amplitude (distance from rest position to crest or trough of wave, crest, trough, wavelength

Question 3

What is the matter called through which mechanical waves travel?

Answer 3

Medium

Question 4

What two factors determine wave speed?

Answer 4

Wave type and it’s medium.

Question 5

Why does the speed of a wave on the surface of water differ from the speed of a sound wave in water?

Answer 5

Refraction.

Question 6

If the frequency of a wave in a given medium doubles, what happens to the wavelength?

Answer 6

The wave length is shortened by half.

Question 7

Describe the three kinds of mechanical waves.

Answer 7

Longitudinal- the vibration of a wave is parallel to the direction of wave movement.
Transverse- the vibration is at right angles to the direction of travel.
Surface/combination - that occur at the boundary of two different media such as air and water and has both longitudinal and transverse motion.

Question 8

In what two ways can a wave bend? What causes the bending in each case?

Answer 8

Reflection and refraction.
In reflection a wave bounces off of a surface that doesn’t completely absorb
its energy.
In refraction the wave moves from one medium to another which changes it’s speed.

Question 9

Two sets of continuous waves traveling in opposite directions pass through each other. What wave interference phenomenon occurs when they have the same wavelengths? when they have different wavelengths?

Answer 9

Constructive interference.

Destructive interference.

Question 10

T or F: Mechanical waves can be classified as transverse, longitudinal, or combinations of the two.

Answer 10

True

Question 11

The speed of sound in room-temperature air is 346.5 m/s. If a musical instrument produces the note A above middle C, which corresponds to a frequency of 440. Hz, what is the tone’s wavelength?

Answer 11

v = speed of wave in meters per second
Wavelength (Lambda) in meters
f = frequency
v= Lambda * f
346.5 = Lambda * 440 Hz
346.5/440 = .788
Wavelength = .788 m