what is dis blogg all about...?...

1. What is a mechanical wave?
2. How are amplitude, frequency, and wavelength related to each other in relation to sound waves?
3. How do waves bend?What is the law of reflection?
4. What makes some sounds louder than others?
5. How are sound intensity and loudness related?
6. What factors determine the quality of a sound?
7. How does your ear work to help you hear sound?

Step 2: Each person in your group will need to do research, in order to gather information necessary for solving the stage lighting and sound problems. A list of Resources for this research is available for you to use to answer your background questions.

Step 3: The background questions page should be used to gather information needed to solve your particular problem. You must research at least three different Internet sites and note the sources (website URLs) of your search.
Step 4: After researching your roles and individually completing your background questions, come together with your other group members to discuss your findings. Decide how the information you collected can help you come up with solutions to the problems faced by the crew of American Senior High. Discuss within your group the solutions that you will propose for each of these problems.

Step 5: With your fellow group members, use the Plan Outlines to write your plan for the Club sponsor and the Principal of American Senior High. explaining the solutions that you recommend to the cast and crew. Remember, these solutions should be both time and cost efficient. Be sure that your written plan describes HOW and WHY your solution will work. Write your plan in a persuasive tone, in order to convince both that your plan will work and will be worth the time and energy investment.

Make a Power point presentation that summarizes all your solutions.

Evaluation
Your Sound and Lighting Crew's final written plan to the Club sponsor and the Principal of American Senior High. will be assessed using a grading rubric. All three sections of your crew's plan will be graded together.
Written Plan: Sound and Lighting Crew Solutions
Group Members Lighting Specialist ___________________Color Technician _____________________Audio Engineer ______________________

CATEGORY
Solutions - Logistics
4. The solutions for all three of the stage and lighting problems are easy to understand, and are logical.
3. The solutions for two of the three stage and lighting problems are easy to understand, and are somewhat logical.
2. The solutions for two of the three stage and lighting problems are a little hard to understand.
1. None of the three solutions are attempted or are impossible to understand.

Solutions- Content
4. The solutions for all three of the stage and lighting problems use appropriate scientific concepts to explain how and why the solutions will work.
3. The solutions for two of the three stage and lighting problems use appropriate scientific concepts to explain how and why the solutions will work.
2. The solutions for two of the three stage and lighting DO NOT use appropriate scientific concepts to explain how and why the solutions will work.
1. None of the solutions use appropriate scientific concepts to explain how and why the solutions will work.

Solutions- Time and Cost Efficiency
4. The solutions for all three of the stage and lighting problems explain why the plan will be time and cost efficient.
3. The solutions for two of the three stage and lighting problems explain why the plan will be time and cost efficient.
2. The solutions for two of the three stage and lighting DO NOT explain why the plan will be time and cost efficient.
1. None of the solutions explain why the plan will be time and cost efficient.

Neatness
4. The final draft of the plan is readable, clean, neat and attractive. It is free of erasures and crossed-out words. It looks like the authors took great pride in it.
3. The final draft of the plan is readable, neat and attractive. It may have one or two erasures, but they are not distracting. It looks like the authors took some pride in it.
2. The final draft of the plan is readable and some of the pages are attractive. It looks like parts of it might have been done in a hurry.
1. The final draft is not neat or attractive. It looks like the students just wanted to get it done and didn't care what it looked like.

Spelling and Punctuation
4. There are no spelling or punctuation errors in the final draft.
3. There is one spelling or punctuation error in the final draft.
2. There are 2-3 spelling and punctuation errors in the final draft.
1. The final draft has more than 3 spelling and punctuation errors.

Powerpoint Presentation

4. Excellent use of graphics and a very good summary of the information capable of maintaining the audience attention during the whole presentation.
3. Good use of graphics and a good summary of the information capable of maintaining the audience attention for most of the presentation.
2. Acceptable use of graphics and a acceptable summary of the information capable of maintaining the audience attention for part of the presentation.
1. Some use of graphics and not summarized information uncapable of maintaining the audience attention for most of the presentation.

Rayleigh surface waves

Rayleigh waves

Rayleigh waves, also known as the Rayleigh-Lamb Wave or "ground roll", are a type of surface waves.They are associated on the Earth with earthquakes and subterranean movement of magma, or with any other source of seismic energy, such as an explosion or even a sledgehammer impact, and are also the form of ocean waves. .
From a condensed matter physicspoint of view Rayleigh waves are surface acounting waves and associated with a huge number of electronic components, the SAW devices, which employ them. SAW devices are mainly used in cellular phones and wireless technology, and their worldwide yearly production is approximated to lie over 1000 million


Abstract

Rayleigh surface waves were discovered theoretically as a solution of wave equation. Their physical existence was confirmed later thanks to numerous experimental investigations and practical applications in acoustics, geophysics, electronics, etc. Conditions of Rayleigh surface waves propagation are defined by one of the real roots of Rayleigh equation. The other real roots of the equation were assumed to be extraneous and were not taken into account. This paper is considering possibility to use additional (extraneous) real roots of Rayleigh equation for explanation of existence of a special type of leaky waves, which propagate on the border of half-space solid and vacuum. Conditionally these waves could be referred to as Rayleigh transformed sub-surface waves as they propagate along the surface, their main energy concentrates in a local zone under the surface, and below this zone they transform into bulk waves taking away the wave energy. Some computer simulations and calculations are presented as a theoretical explanation of conditions of Rayleigh transformed sub-surface waves propagation. Keywords: acoustics, Rayleigh equation, surface waves, ultrasonics, phase velocity.


Introduction

Physical Acoustics as fundamental science was born about two hundred years ago thanks to monumental works of great scholars: Rayleigh, Lamb, and Love [1, 2, 3]. The second part of the 20th century demonstrated high performance acoustic applications in several fields of science and technology. Ultrasonics as a branch of acoustics is one of the main consumers of physical acoustics fundamentals. The latest advances of electrical and electronic engineering gave opportunity to build a wide class of ultrasonic equipment allowing verification of basic acoustic concepts. Some recent experimental results cannot be explained unambiguously by existing basic theories especially in the field of acoustic surface waves classification. Depending on classification of the wave type testing results may be interpreted differently. In spite of the fact that a lot of basic and experimental works are published on the problem of analysis and classification of Rayleigh type surface waves, distance between theoretical models and real materials is hard to come by.


Theoretical Background

Transformed surface (TS) waves are a recently discovered [4,5] special class of elastic waves in solids. This class of waves is intermediate between bulk and surface waves, which propagate along the border of solid medium and transform acoustic energy from surface co-boundary space or into the solid depth. Their characteristic behavior may be described as follows: they appear in a local area near the energy source, propagate further with splitting into bulk and surface wave components, have limited zone of propagation because of fast energy transformation from surface to bulk component and absorption and dissipation of energy in solid.
It is possible to distinguish a sub-class of TS waves, which have got a name of "leaky surface waves" (LSW). At present two types of the LSW have been investigated: waves on the border of two solid half-spaces with different physical properties and on the border of solid half-space and liquid. The first type of the LSW could be presented by Stoneley waves [6]. In the case of Stoneley waves acoustic energy is leaking from one solid half-space to the other, and the wave propagates on the border between them. The second type of the LSW could be presented by Rayleigh type of waves: on the border between solid half-space and liquid [7]; and Lamb type of waves in plates immersed into liquid [8]. In this case acoustic energy is leaking from half-space solid or plate to liquid [9].

The radius of the circles decreases as the depth of the water

Longitudinal and Transverse Wave Motion

Mechanical Waves are waves which propagate through a material medium (solid, liquid, or gas) at a wave speed which depends on the elastic and inertial properties of that medium. There are two basic types of wave motion for mechanical waves: longitudinal waves and transverse waves. The animations below demonstrate both types of wave and illustrate the difference between the motion of the wave and the motion of the particles in the medium through which the wave is travelling.

Longitudinal Waves

In a longitudinal wave the particle displacement is parallel to the direction of wave propagation. The animation below shows a one-dimensional longitudinal plane wave propagating down a tube. The particles do not move down the tube with the wave; they simply oscillate back and forth about their individual equilibrium positions. Pick a single particle and watch its motion. The wave is seen as the motion of the compressed region (ie, it is a pressure wave), which moves from left to right.

water waves

Water waves


Any disturbance can cause a water wave. A pebble striking the surface, movement of a boat, movement of the earth during an earthquake, or the wind. Here we focus on wind generated waves, although the same principles apply to all water waves.

Fetch is the distance over which the wind interacts with the water surface to creates waves. The longer the fetch the bigger (higher) the waves are. If the shore (green in the diagram) is a hill, there will be a wind shadow which gives protection from the wind, but even if the shore is flat as a pancake and gives no protection, the waves become progressively smaller as you for upwind to the shore. Thus, rowing upwind toward shore is always an escape from waves.

Height and Length of a simple wave (also called a sine wave) are indicated on the left. On the real water the surface often doesn't have this simple shape, rather the surface is the combination of waves with different lengths and heights.

Motion of the water is different than the motion of the wave. Water at each location moves in a circular path, but the motions at different locations are "out of phase", which means that when water at the left of the diagram is moving to the right, water a quarter of a wavelength to the right is moving down, and water next to it is moving to the left, and next to it is moving up, etc. The overall effect is a an "apparent" wave moving to the right. Thus, the velocity (speed) of a wave is not at all the same as the velocity of the water.
The horizontal movement of the water when a wave passes is approximately equal to the up and down movement of the water. If you are on flat water and are parallel to waves made by a passing boat, your boat will move side-to-side as much as up-and--down as the wave passes under you. The side-to-side movement actually creates most of the difficulty in balancing the boat in such a situation. However, under typical conditions in the bay there can be such varied wave action that you can't easily distinguish horizontal and vertical motion

the different kind of waves

Different kind of waves

waves travel on the surface of the water. You can see them. As you swim through the water, you can even make your own waves.

the first kind of body waves is the O wave or primary waves. This is the fastest kind of seismic wave, and, consequently, the first to 'arrive' at a seismic station. The P wave can move through solid rock and fluids, like water or the liquid layers of the earth. It pushes and pulls the rock it moves through just like sound waves push and pull the air. Have you ever heard a big clap of thunder and heard the windows rattle at the same time? The windows rattle because the sound waves were pushing and pulling on the window glass much like P waves push and pull on rock. Sometimes animals can hear the P waves of an earthquake. Dogs, for instance, commonly begin barking hysterically just before an earthquake 'hits' (or more specifically, before the surface waves arrive). Usually people can only feel the bump and rattle of these waves.

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