Explore BrainMass

EM Waves

Electromagnetic radiation and waves are a form of energy emitted and absorbed by charged particles which exhibits wave-like behavior as it travels through space. EM waves have electric and magnetic field components, which stand in a fixed ration of intensity to each other, and which oscillates in phase perpendicular to each other and perpendicular to the direction of energy and wave propagation. In a vacuum, electromagnetic radiation travels at the speed of light.

Electromagnetic radiation is a form of electromagnetic fields which is produced by moving charges. It is associated with EM fields that are far enough away from the moving charges that produced them. It carries energy through space continuously away from the source. It also carried both momentum and angular momentum. These properties are important to matter with which it interacts.

In classical physics, ER is considered to be produced when charged particles are accelerated by forces acting on them. The electrons are responsible for emission of most EMR due to their low mass which makes them easily accelerated by a variety of mechanisms. Quantum processes can also produce EMR. This can happen when atomic nuclei undergo gamma decay and processes such as neutral pion decay.

The effects of EMR on biological systems depend upon the radiation’s power and frequency. Lower frequency of EMR up to visible light have damage determined by the heating effects and thus by the radiation power. In contrast, for higher frequency radiation at ultraviolet frequencies and above can damage the chemical materials and living cells by EMR is far larger than that done by simple heating. This is due to the ability of single photons in such high frequency EMR to damage individual molecules chemically.

Maxwell's Equations and the Wave Equation

The question attached is from this page. Please answer with vector notation. The question is only about (450) so I don't believe that you have to read through all of it to answer.

Charge distribution of the Hydrogen atom

Please see the attach file for the full question. The time-averaged potential of a neutral hydrogen atom is given by 4s (1 + 7) wo r where q is the magnitude of the electronic charge, and cx-' = ao/2, ao being the Bohr radius. Find the distribution of charge (both continuous and discrete) that will give this potential and inte

Social Cultural Legal and Political Influences

Read the Case Study "The Nonmarket Environment of Google" and complete the following: • Identify 4-6 specific examples of each of the "Four I's" in the case (issues, interests, institutions, and information). • Identify where three of the issues are in the nonmarket life cycle. SOCIAL, CULTURAL, LEGAL, POLITICAL INF

Food Chain, Food Web, and Lake Michigan

Most biological energy here on Earth can be traced back to one single source: the sun. Plants and blue-green algae use photosynthesis to trap the electromagnetic wave energy generated by the sun, transforming it into chemical energy in the form of food for themselves and for other creatures that eat them. Sounds simple so far

Radiative Heat Transfer: Wien's Displacement Law

At what wavelength do the planetary bodies and Sun have their maximum emissive power? What range of the spectrum does this fall in? As the surface temperature increases, does the wavelength increase or decrease? What is the maximum temperature required for the maximum emissive power to enter the microwave range? What is the mini

Loss of Vision and Motor Control

Analyze the loss of vision: ? Describe the loss of vision and the effect that it has on behavior. ? Discuss the physiology associated with the loss of vision. ? Describe at least three case studies concerning this topic and the findings from these case studies. ? Explain the importance of continued research concerning t

Alternating Current and Direct Current

Discuss alternating current and direct current in following aspects. (1) How it is created, including descriptions of all components required. Illustrate with labeled diagrams. (2) A labeled diagram of its waveform. (3) Magnetic effects. (4) Typical uses in everyday world. (5) Typical uses in building services engine

Transmission Lines, Electromagnetic radiation and propagation

1- Find the characteristic impedance for a coaxial cable with an inductance of 64 nH/ft and a capacitance of 43 pF/ft. 2- A coaxial cable has an inner diameter of its outer conductor of 0.5 in. The outer diameter of its inner conductor is 0.1 in. The cable is filled with Teflon. Find the characteristic impedance. 3- A coax

What are the five senses? What is the nature of sensation and perception as they apply to the five senses? What physical properties do these senses represent? Are the senses veridical (truthful) representations of the physical world? Why or why not?

In order for the senses to be representations of the physical world, people would have to step outside themselves (meaning outside perceptual constraints and representations) and evaluate the extent that their perceptual representations resemble the physical world. A person's percepts, judgments and observations of the physical

Physics Phenomenon of beating: sound of a siren, beat frequency of two sounds

See attached file for formulas. Temporal interference results from the superposition of two waves having slightly different frequencies. When the two waves are observed at a point in space, there is a temporal (time) alternation between constructive and destructive interference. If, for example, two tuning forks of slightly

Risk Management Trends and Developments

Write 1,500 words in which you examine at least three new trends and developments in risk management. Examine future challenges to risk management strategies. Make sure to address the following in your own words from outside sources: Summarize each trend and development. Discuss the significance of each with pros and cons.

Survey on osteosarcoma.

Hi, I am trying to do a survey and I can't think of some questions to ask my nephews and niece. My brain is stomp right now. I need a start on what kind of questions to ask them. I can't even think of the first question. Their mother died from osteosarcoma. So please help me to figure it out. I would need 20 questions but if you

Problems Involving Electric and Magnetic Fields

See attached file for problems. 1. Every point on the wave executes an up down simple harmonic motion about the mean position. The point rises up, reaches the peak (crest) where it comes to rest momentarily, reverses direction and starts moving down reaching the lowest point (trough) where again is comes to rest before re

Cerebral Cortex & Evolution of the Motor Cortex

What regions in the cerebral cortex are known to be involved in movement? How do these areas contribute to the production of motor behavior? Located at approximately mid-brain and at the very back of the temporal lobe is the motor cortex, which is the area of the cerebral cortex that controls voluntary movements (Dubuc, 2008

Evolutionary Perspective, Adaptation, Sensory Systems & Brain Receptors

1.How adaptation is important from an evolutionary perspective? 2.Describe in detail the theories surrounding one of the sensory systems in regards to how we smell, touch, taste, see, etc. 3.Comprehensively describe the sensory systems- touch and taste, from the receptors all the way into and including the brain.

Marketing Management: Bose Corporation analysis of strategy and philosophy

Please see full case in attached file. This is a master level report and case study analysis of Bose Corporation discussing about the company's marketing strategies and business philosophies. Attached its case study and synopsis with questions. Basic requirements and guidance by lecturer have been written in red below each

A Proposal and Recommendation in Argument is given.

This posting explores these inquiries: 1) In Intuitive Eating, analyze its introduction. What sort of introduction does the author use? How does it fit with the author's goals for the proposal? Is it successful? 2) In Daemon Seed, analyze its conclusion. What sort of conclusion does the author use? How does it fit with th

Police - Interrogation of Terrorist

Should U.S. Police Forces, which are severely restricted in how they can interrogate and use electronic surveillance, be granted more freedom and power in order to implement counter-terrorist measures? Consider the possible ramifications of your answer.

Plane Wave Propagation

This is a multiple choice question on plane wave propagation in electromagnetic field as found in the attached file.

Impedance of RLC circuit, electromagnetic wave

1) Under what conditions is the impedance in an LRC circuit a minimum? 2) At a given instant in time, a traveling electromagnetic wave is noted to have its maximum magnetic field pointing west and its maximum electric field pointing south. In what direction is the wave traveling? If the rate of energy flow is 500W/m^2, wh

Superposition of Waves

The broadcast antenna of an Am radio station is located at the edge of town. The station owners would like to beam all of the energy into town and none into the countryside, but a single antenna radiates energy equally in all directions. The attached figure shows two parallel antennas separated by a distance L. Both antennas bro