Let+us+Entertain+you-+Chapter+5

SECTION 1:
Guitarists and violinists make different sounds with their instruments, by strumming and playing different chords or strings. They also apply different amounts of pressure to each different string. If a guitarists wanted to play a high pitched sound they would place their fingers higher and closer together.
 * WHAT DO YOU THINK NOW: **

To produce sound something must vibrate. Length and tension affect the pitch of the sound of a vibrating string. Shortening the string resulted in a higher pitch. Also, when you add mass to the mass hanger on the end of a string, the pitch also changed. As tension increases the pitch also increases.
 * PHYSICS TALK SUMMARY: **

1) The pitch increases and gets higher as the tension is increased 2) It will become a higher pitch. The shorted the length the higher the pitch 3) This increased the tension, which increased the pitch 4) The object that is struck vibrates to produce a sound.
 * CHECKING UP QUESTION: **

1a) adding or taking away mass 1b) increase the tension increases the pitch; decreasing the tension decreases the pitch 2a) One could shorten the string by moving their finger or hand 2b) decreasing the length increases the pitch; increasing the length decreases the pitch 3a) Increasing tension and increasing length 3b) Decrease the length and decrease the tension 4) It would be very high pitched or very low pitched depending on where and what you did. The sound would be different though 5a) They play on different frets and place their hand in different positions for every different note. Also they place their hands on different strings 5b) They tighten the wires and they listen to the sounds of the notes to see if they sound the same 6a) They make the strings looser or tighter. They change the sound of the notes and the key the guitarist is playing in 6b) It needs tuners in order to play different notes 6c) The pitch will decrease 7a) Frets tell the guitarists where to place their fingers in order to play different notes and sounds 7b) no 7c) They do not have frets on the instrument, and they have to remember the sounds and hand placing in order to play the same song again. It is more memory By increasing or decreasing the length on strings of instruments, violinists and guitarists are able to make different sounds when playing their instrument. When in need to play a very high pitched note on a guitar lets say, the guitarists would put their fingers closer to the center and make the string length shorter and shorter. To increase the pitch one would have to increase the tension of the string.
 * PHYSICS TO GO: **
 * WHAT DO YOU THINK NOW: **

SECTION 2:
Water moves up an down and side to side to make a wave. When a wave crashes, it is coming in contact with another wave. Each particle moves up and down to make the wave.
 * WHAT DO YOU THINK: **

A wave is a transfer of energy with no net transfer of mass. A coiled spring is the medium through which the wave travels and through which the energy is transferred. For water the medium if the surface of the water. As water moves up and down, the wave moves out from the center of its course in concentric circles. Waves add as they pass each other, and than they continue to travel. Periodic wave: a repetitive series of pulses Crest: the highest point on the periodic wave Trough: the lowest point on the periodic wave Amplitude: The maximum disturbance--> the height of the crest or the depth of the trough. Wavelength: the distance from one point on a wave to the same point on the next Wave Speed: total distance/total time or wave length*frequency Transverse Wave: sine curve, move side to side --> energy of the wave is vertical Longitudinal Wave: moves up and down - energy in same direction as particle motion Pulse: one single disturbance in the medium Traveling Wave; regular and repeating motion Node: A point on a standing wave where the medium is motionless Anti-node: a point on a standing wave where the displacement is the largest
 * PHYSICS TALK SUMMARY: **

1) A wave is a transfer of energy with no net transfer of mass 2) A transverse wave is a wave in which the motion of the medium is perpendicular to the motion of the wave. A longitudinal wave is a wave in which the motion of the medium is parallel to the direction of the motion of the wave. 3) A node is a point on a standing wave where the medium in motionless. An anti-node is a point on a standing wave where the displacement is the largest
 * CHECKING UP QUESTIONS: **

1a) 1b) The amplitude and wavelength are measured in meters. Frequency is measured in Hz. Also speed is measures in m/s 1c) Frequency, wavelength, and speed are all related due to the formula for speed. V=wavelength X frequency 2) Frequency will increase; wavelength will decrease; speed will remain the same; Amplitude would remain the same 3) You would measure the distance from one peak to the next. You would measure this you a meter stick or a ruler 4) You would count the number of waves that pass the assigned point in a certain period of time and than you would convert to the proper measurement which would be Hz. 5a) Meters 5b) Hz 5c) M/s 5d) wave speed= wavelength(frequency) 5e) Wave speed is measured in m/s. You get this when you multiply frequency and wavelength 6a) A standing wave which is also called a stationary wave is a pattern that remains in a constant position. 6b) 6c) The wavelength is determined by looking at a standing wave and measuring the distance between two nodes 7a) Transverse wave: a wave in which the motion of the medium is perpendicular to the motion of the wave. A longitudinal wave: a wave in which the motion of the medium is parallel to the direction of the motion of the wave. 7b)
 * PHYSICS TO GO: **
 * 8 **** a) Shake it faster **
 * 8b) Shake it slower **
 * 9 **** a) 10m, 5, 10/3m, 5/2m, 2m **
 * 9b) Frequency has to increase **
 * 10 **** a) Wavelength is 20 m **
 * 10b) 1/2 s/cycle **
 * 10c) 10 m/s **
 * 11 **** a) 3+2 = 5 cm **
 * 11b) 3-2 = 1 cm **
 * 12) v = distance/time **
 * v = 4.5(2)/2.64 **
 * v = 3.41 m/s **
 * 13 **** a) nodes **
 * 13b) 6 m **
 * 13c) make it a 6 harmonic **

A wave begins on the surface of water and then rises to reach a certain amplitude of height. Once it reaches that height the wave moves like a transverse wave, back towards the surface of water and then back again to the same amplitude under the water. The next wave may come up from that exact point and the cycle would repeat over and over again. Each particle moves up and down to make the wave as well.
 * ACTIVE PHYSICS PLUS: **
 * WHAT DO YOU THINK NOW: **

SECTION 3:
When the tension in the string is increased, the pitch will become higher. This occurs because the string has a smaller place to move vertically so the sound increases **. **
 * WHAT DO YOU THINK? **

The length of the string determines the wavelength of the standing wave. The pitch that you hear is related to the frequency of the wave. The higher the pitch the higher the frequency. To get a higher frequency you have to shorten the string. Wave speed- wave frequency X wavelength The shorter the wavelength is the higher the frequency--> inverse relationship Increasing the tension does not increase the wavelength, it stays the same. By adding mass it changed the pitch and frequency. The speed of the wave increases when the wavelength does not change but the frequency does. Increase in tension produces a larger force. Increasing the wave speed increases the frequency and pitch. L=n(wavelength)/2
 * PHYSICS TALK SUMMARY: **

1) Decreasing the wavelength makes the frequency and pitch increase --> Inverse relationship 2) Tension increases so does the pitch 3) The weaker the tension is, means the slower the wave speed. 4) L = 1/2n(wavelength)
 * CHECKING UP QUESTIONS: **

Pitch changes when you alter the tension in the spring because the speed increases which results in more waves per second. When frequency increases, the pitch is also higher, because pitch and frequency are the same thing. The speed increases when tension increases because the particles are closer together so they respond to each other faster. The frequency and tension have an inverse square root relationship, meaning that when you increase the tension the frequency decreases and when you decrease the tension the frequency increases.
 * WHAT DO YOU THINK NOW: **

SECTION 4:
Flutes and organs produce their sound through air traveling through the tubes due to anti-nodes and nodes. Sound is a compressional wave. The molecules of air squeeze together or spread out as the sound wave travels through the air. At the open end of the test tube the amplitude of the wave is the largest it can be. The vibration of air at the open end makes a sound wave that moves the test tube to your ear. This point is an anti-node of the standing wave. Sound waves travel by spreading out or bending around barriers. The ability of sound waves to spread out or change direction as they emerge from an opening is called diffraction. __**Closed end of a tube: node**__ > pitch and frequency decrease > wavelength is 1/4 __**Open end of a tube: anti-node**__ > both sides are open--> it forms a vibrating column of air > displacement of the air molecules are zero > wavelength is 1/2
 * WHAT DO YOU THINK: **
 * PHYSICS TALK SUMMARY: **

1) The sound traveling in the air is the medium. The sound diffracts while traveling throughout the air. Sound can travel through different size barriers and boundaries, because it goes through the barrier and than spreads throughout space. 2) Waves are able to diffract by bending and finding different openings to go through. In order to fit through the barriers and boundaries they can switch directions and move together in order to move through bigger or smaller places. 3) Wavelength X frequency = speed. When speed is constant, the frequency and wavelength are also constant.
 * CHECKING UP QUESTIONS: **

1a) Similarities--> caused by standing waves, harmonics are octaves apart, changing length of string vs. tube effect the frequency 1b) Differences-->string moves the air vs. mouth moves the air ; string (nodes at both ends), tubes (node and antinode) 3a) 11 meters 3b) 3c) open pipe: 22 meters, closed pipe: 44 meters 3d) Wave length and frequency are indirectly related when speed remains constant. v = wave length * frequency 4a) 12 meters 4b_ 340/12 = 28.3 Hz 4c) 6 meters 4d) 340/6 = 56.6 Hz 5) The frequency would be a lot higher because the pipe is 1/3 the length of the previous 3 meter pope 6a) Diffraction 6b) 8) v = d/t 340 = 1600/t t = 4.71 s
 * PHYSICS TO GO: **
 * WHAT DO YOU THINK NOW **