"to find any other harmonics, will it always be as easy as multiplying by the fundamental harmonic or is there some formula to use?"

"When changing octaves what is the degree of change?"

"Can you explain what overtones are? "

"Are there only the 2 equations (x=vSin(wt), etc.)that in this chapter that help us solve for a variety of variables?"

"Can you explain more on how waves add together and then what they look like"

"I guess I don't understand the principle behind constructive and destructive interference of waves. Can you have both occurring during superposition of a wave?"

"Can we go over those wave combinations again?"

**Reflection**

**Interference and superposition**

**Standing wave**

**Waves**

**Refraction and diffraction**

**Review wave speed**

**Intensity of a wave**

(amplitude)

always reflection, can have phase change

Add together, constructive, destructive, in between

save for PH 106 and light

P and S waves from an earthquake travel at different speeds, and this difference helps locate the earthquake epicenter.

Assume typical speeds of 8.5 and 5.5 km/s, how far away did an earthquake occur if a particular seismic station detects the arrival of these two types of waves 1.5 min apart?

Two children are sending signals along a cord of total mass 0.50 kg tied between tin cans with a tension of 35 N. It takes the vibrations in the string 0.55 s to go from one child to the other. how far apart are the children?

If the intensity of a sound source is 0.01655 W/m^2, as measured by a person that is 25 m away, What is the power of this source?

What would be the intensity as measure by someone who is 35 m away?

A certain amplifier can use up to 130 W of power. It is known that damage can occur if the intensity of sound gets above 15 W/m^2. How close would you need to be to this amplifier to cause damage to your ears?

Rock concerts have a typical intensity of about 1 W/m^2, what distance from the previous amplifier would cause this intensity?

A violin string vibrates at 294 Hz when unfingered. At what frequency will it vibrate if it is fingered one-third of the way down from the end near the pegs.

A mass is hanging vertically from a very thin cable having a mass of 75 grams where it is exposed to the wind. It is noticed that the cable 'hums' to a frequency of 284 Hz in the 2nd overtone on certain windy days. If the cable is 1.25 m long, how heavy is the mass?

While tuning with an orchestra, a cellist notices that his 1.2 m strings having a linear density of 5 g/m starts vibrating in is 3 harmonic due to another instrument playing a 441 Hz note. What is the tension in his string?

**Two wires are anchored at both ends. Wire 1 has a mass of 92 gm and a length of 6.6 m. Wire 2 has a mass of 50 grams, a length of 20 m, and a tension of 151 N. What must be the tension (to the nearest Newton) in Wire 1 if its third harmonic is to equal the first overtone of Wire 2**

1400 km

21.2 m

130 W

.00844 W/m^2

83 cm

3.2 m

441 Hz

343 Kg

622 N

40.7 N

n=3

"I don't understand the idea of harmonics"

"If the fundamental frequency on a specific string is 240 Hz, what is the frequency of the 3 harmonic? (answer should look like '240 Hz')"

"I'm not sure how to tell the difference between the in phase and out of phase waves"