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Why does it take longer to boil potatoes in a high-altitude environment such as Denver than in a low-altitude environment such as San Diego?

In a high-altitude environment, water boils at a lower temperature due to decreased pressure. With lower atmospheric pressure, water molecules have weaker bonds, and it boils at decreased temperature (185 degrees Fahrenheit). Nonetheless, potatoes boil at a specific temperature (210 degrees Fahrenheit). Hence, potatoes will need more time to cook.

Describe some of the approaches to disinfection or sterilization.

Sterilisation with radiation:V radiations can inactivate microorganisms but have low penetration. Gas or vapour disinfectant through space decontamination: Uses chemicals (methyl bromide, formaldehyde, hydrogen peroxide etc.) in controlled humidity and temperature. Chemical disinfectants: used for heat-sensitive materials like instruments. Examples are alcohol, halogens, formaldehyde, and glutaraldehyde. Incineration: burning of solid...

What is the occupational exposure standard for noise?

Shown below is a table for the AS /NZS 1269 exposure standard. This varies slightly from the figures quoted by the ASCC/ NOHSC or OHS 2001 regulations for NSW. The latter regulation states that the exposure standard for noise for 8hr Leq is 85 dB(A) with peak values of 140...

Describe the main types of ionising radiation.

The main types of ionising radiation: Ultraviolet radiation-an electromagnetic radiation that comes from the sun and other hot objects. Has UV-A (400-315) and UV-B (315-280nm). UV-B are more harmful as they lead to sunburns. It can be shielded through the use of clothes. Alpha articles-comes from the atomic nucleus, can...

What is WBGT? How is it measured?

WBGT stands for Wet Bulb Global Temperature, and it is useful in controlling and assessing heat stress in workplaces. This is done through the use of a natural wet bulb (NWB), dry bulb (DB) and a globe temperature (GT) reading. Together, these measurements are used to calculate the WBGT. The...

Describe the components of a respiratory protection program.

There should be a head that is chosen by management; he or she must have professional and technical knowledge of workplace hazards and should make decisions that are based upon the evaluation. The program should start with the selection of the right respirator. Medical screening of staff and a training...

What are the main respirator types? When are they used?

Supplied air respirators and air-purifying respirators are two major types of respirators in use. The supplied air respirator works by delivering air to the wearer from another source. They may be airline (pressurised) or hose (non-pressurised). They are appropriate for places with low oxygen levels. The pressurised devices may depend...

List some of the reasons for poor compliance with personal protective equipment.

Personal protective equipment may be deemed uncomfortable due to its weight, size, temperature and the illusion of isolation (as created by hearing protectors). Sometimes certain interferences may minimise compliance, such as spectacle frames and hats. If workers do not know how to use PPE or how it works, then they...

How is daily exposure to noise measured?

Daily exposure to noise is measured through a sound level meter or a dosimeter. The dosimeter consists of a small device that assesses noise when placed near a worker’s ear. Hearing protection is usually recommended when the noise exposure surpasses standard exposure levels. Measurement of run-time, Leq (A), dose, LinPeak,...

Describe some of the measurement problems associated with noise dosimetry.

Sometimes administrative noise controls may be instated, or there could be work patterns that require different considerations. Dosimetry does not consider these fluctuations. Employees’ sources are never recorded through this method, yet these could affect requirements for hearing protection. Time histograms normally help with these as they identify task-related noise...

What is ultrasound? How is it measured?

Ultrasound is defined as sound that exceeds human hearing; this is any frequency that is greater than 20,000Hz. However, it must have a short wavelength of approximately 17mm for 20kHZ in air. Such a sound would have a velocity that is equal to audible sound (343m/s) in the air but...

How does ionising radiation differ from non-ionising radiation?

Ionising radiation differs from non-ionising radiation because of its energy levels. Ionising radiation can ionise matter owing to its high energy levels and may also cause an atom to have an electrical charge. Normally, this arises from an imbalance in the charge or energy in an atom after an electron...

Describe the main types of non-ionising radiation.

Non-ionising radiation can be found in electromagnetic spectrum range and include; extremely low-frequency fields (ELF), Super high (SHF) or extremely high fields (EHF), Ultra-high and very high (UHF, VHF), Medium (MF), Low frequency and very low frequency (LF, VLF), microwaves and radiofrequency waves (RF).

How is ultraviolet radiation measured? How is ultraviolet radiation controlled?

Ultraviolet radiations are measured using either long-term or short-term measures. In long term measurements, one can use photosensitive plastic, polysulphone film badges and a UV dosimeter. Short term measurements include UV spectroradiometers and UV radiometers. One may use a practical approach through the use of proper PPE such as sunscreens,...

Explain sound intensity.

Sound waves transfer energy from one place to another, which is to our ears through a specific medium such as solid, liquid, or gas. Sound intensity is used to gauge the rate of the energy traversed at a certain point. The sound intensity is defined by the equation shown below:...

What is a harmonic wave?

Harmonic wave is a physical term describing an oscillatory motion or vibration which moves first in one direction and then back again in the opposite direction. An example is the movement of a string plucked in a musical instrument. In addition, the harmonic wave is usually accompanied by sound production....

Explain the term acoustics.

Acoustics is a term used to describe the physical characteristics of sound. Unlike other techniques of studying sounds such as x-rays and tracheal punctures, acoustics provides a non-invasive way of describing the characteristics of speech. It has tremendous application in describing sounds that may be difficult to characterize in articulatory...

Discuss the classification of acoustic waves.

There are three types of acoustic waves namely; surface waves, seismic waves, and longitudinal waves. Most importantly, minor breaks can be detected on time before serious damage occurs. Moreover, surface acoustic waves are used in frequency amplification to filter signals. Such signals assist in the demodulation of noise in the...

Discuss the physical characteristics of sound waves.

The four basic qualities are important concepts in understanding sound and music. The amplitude, also described by the loudness or musical sound is a relative measure of the strength of the sound that is heard. The loudness of music is fundamentally related to the distance from the source as well...

Explain, what is tone quality?

Sounds are characterized by a fundamental frequency and harmonics which are quite complex. If the frequency of two different instruments happens to be similar, there is a likelihood of getting a similar pitch. Tone quality is also determined by the beginning and end of the tone.

Low and Negative Thermal Expansion

What is the difference between low and negative thermal expansion materials? The paper should include: Physical principles behind these materials in the context of condensed state physics. Special properties of these materials and why one would be interested in those materials. The latest research on such materials. Techniques in tuning...

Describe the Materials with Low and Negative Thermal Expansion

Talk about the condensed state physics of material with low thermal expansion and negative thermal expansion. Focus on near zero thermal coefficient materials (NZE), while negative thermal expansion materials (NTE) is an auxiliary topic. The paper should include: physical principles behind these materials in the context of condensed state physics,...

Study the Materials with Low and Negative Thermal Expansion

Talk about the condensed state physics of material with low thermal expansion and negative thermal expansion. Dwell upon physical principles behind these materials and their special properties, techniques in tuning materials to lower thermal expansion coefficients to near zero or negative as well as examples of near-zero thermal coefficient materials...

What Are the Three Learning Activities and Renewable Energy?

Review the following three Learning Activities: “Solar, Wind and Biofuels”, “Hydropower and Geothermal” and “Nuclear Power.” Then, introduce a definition in your own words for renewable energy, and argue with ideas presented in the reading for why nuclear power does not meet your definition for a renewable energy. Which renewable...

Summarize the complete lifecycle of the Sun.

About 4.5 billion years ago due to the collapse of a hydrogen molecular cloud, the Sun was formed. The solar formation was created in two unique ways, by using computer models based on Stellar Evolution we can determine the age of the Sun. We also use the radiometric data for...

What does ΣF =0 mean?

According to the equilibrium rule, an object is at a state of equilibrium when all the forces acting on an object are balanced. This occurs when the net force of the object is zero. In the equilibrium state, the object is either moving in the same direction or being at...

Why is support force on an object normally called the normal force?

A normal force is a responsive push-back force that acts in response to a pull or push. The upward force that balances an object’s weight on the surface is the support force. This force is also called a normal force because it exists in response to a force from another...

What equation shows the relationship between speed, distance, and time?

The force arising between two objects in contact, which always acts in the opposite direction to a push, is friction force. Speed is a scalar quantity. It is defined as the rate at which distance is covered by an object. On the other hand, the rate at which position changes...

In your study of the pure tones. Did you notice that for some sounds, the tones seemed extremely loud while others sound quite hard to hear? Does the spectrum analyzer SL Intensity results agree with your perceived level of sound intensity?

The different tonal frequencies generated sounds of varying intensities and loudness; in other words, frequency has a significant impact on the loudness of sound. The pitch of the different tones picked up by the ears aligns with the SL intensities reflected in the spectrum analyzer. For instance, the perceived level...

Why should we expect quasars to be small? How small?

Quasars are the glowing part of distant galaxies; they achieve this by emitting electromagnetic radiations of very high frequencies detectable as bright light. According to Einstein’s energy equation E=MC2, an object emitting high energy will continuously reduce its mass as it discharges more energy and will cease to be matter...

What role does your hearing response play? What role does the speaker or microphone response play? Try playing the files through headphones. Do you hear a greater range of tones? If you put the device with the Spectrum analyzer application near the headphone, does it have the same relative SL intensity at all frequencies?

The ear plays the role of a frequency receiver, and this is facilitated by its capability to identify and distinguish pure tones. On the other hand, the speaker and microphone serve the function of a frequency channel. The form is the pathway through which frequency travels from the source to...

Light is one form of electromagnetic radiation. What are electromagnetic waves and what other types are there besides visible light?

Electromagnetic waves consist of two components. One is electrical and the other is magnetic. Their speed is equivalent to that of light (300000 kilometers/sec) when they travel through space. Light contains waves that have wavelengths of about 10-7 meters. Other types of electromagnetic radiations are X-rays which have shorter wavelengths...

Why do astronomers infer that the Sun’s energy comes from nuclear fusion reactions rather than chemical reactions? How do we know it cannot possibly come from a chemical process? Who was responsible for proposing nuclear energy powers the stars?

Astronomers believe that the source of the Sun’s energy is nuclear fusion reactions because the age of the sun is estimated to be at least 4.54 billion years. No chemical reaction can sustain itself for such a long time. We know it for sure because the temperature at the core...

Briefly describe a Hertzsprung-Russel diagram and give some examples of where and why some planetary objects appear on the diagram.

A Hertzsprung-Russell diagram refers to an illustration in which the absolute magnitude or essential brightness of stars are plotted vertically against the surface temperatures or corresponding spectral types. There seems to be a strong connection between brightness and surface temperatures, with types of blue stars having higher luminosity and types...

Why do animals’ eyes glow green when illuminated at night?

For many years, historians and poets have been fascinated by the green color that appears when the eyes of different animals get into contact with light at night. Unlike human beings, animals’ eyes tend to glow when illuminated at night. Jenkins indicates that the occurrence is caused by a layer...

Explain how Type I and Type II supernovae occur.

Supernovae are a stage in the evolution of stellar objects, which ends with a bright explosion of the star, and the object ceases to exist. The explosions of supernovae are divided into two main types – type I and II. According to Thompson, they are distinguished by the presence or...

“A Star Is Born!” In a step-by-step fashion, reconstruct the birth of a star. In your answer, include interstellar medium, protostar, and how stellar equilibrium is finally reached.

In the interstellar medium, there is a continuous counteraction between two tendencies – compression and expansion. The compression of the cloud is facilitated by its own gravity and external forces, for example, the explosions of neighboring stars. The expansion is developed due to the pressure of the gas and magnetic...

Explain how the Hertzsprung–Russell diagram is constructed of the four main groupings of stars. Identify the characteristics of the four main groupings of stars on the diagram.

The most famous visual tool in astronomy is the Hertzsprung-Russell diagram. This mechanism shows the dependence of luminosity with respect to the spectral class of the star, starting from high and blue-white stars on the left side of the diagram to the low temperature indicated by red stars on the...

Describe the sun in terms of its structure and activity. Include in your discussion the following terms: sunspots, prominences, solar flares, solar wind, core, radiative zone, convective zone, and photosphere.

The central part of the Sun’s internal structure is its core, where a nuclear reaction of the conversion of hydrogen into helium takes place. In the course of these changes, energy is released, which is ultimately emitted from the surface of the Sun in the visible region of the spectrum....

Consider the validity of the Hubble sequence in modern astronomy. What observations contradict the theory of galactic evolution? What observations support the theory of galactic evolution?

The Hubble sequence is an old classification of galaxies but is still relevant. The Hubble sequence is used in professional astronomical research and amateur astronomy. The main remark about the Hubble sequence is that it does not fully cover the variety of galaxies. Also, the sequence does not take into...

Compare and contrast size, composition, structure, and history of at least 2 specific galaxies. Describe how characteristics of these galaxies contributed to the Hubble sequence.

The Andromeda galaxy is Sb in the Hubble sequence; the Milky Way galaxy is SBbc. The selected galaxy Size Composition Structure History Galaxy Milky Way Diameter: 30,000 pc; Thickness: 1000 light years. Contains stars, constellations, gas and dust. Spiral-shaped, with a black hole in the middle. In the 18th century,...

Describe two to four characteristics of the three major types of galaxies.

First, about the form: elliptical galaxies have an oval shape. More than half of all existing galaxies are spiral galaxies. The rest can be attributed to galaxies of irregular shape. Core and branches: elliptical galaxies have no central nucleus and spiral branches. Spiral galaxies have nuclei and branches consisting of...

a. An electron is accelerated towards a copper target anode with an accelerating voltage. It is stopped in a single impact. Write down an equation for calculating the minimum wavelength of the X-ray in terms of the accelerating voltage. Define all the terms in your equation. b. The magnitude of the accelerating voltage used in a. is increased. What happens to the (1) minimum wavelength of the X-ray radiation? (2) Intensity of the X-ray radiation?

a. λ=hc/E, where λ=wavelength of X-ray produced, h=planks constant, E=energy (eV) e is electron charge, c=velocity of light.b. (1) shorter wavelength, (2) intensity increases.

What are pyroclastic materials?

Pyroclastic material often appears during (or rather is a result of) a volcanic eruption. It consists of volcanic rock, ash, lava, and gases. These materials come in a cloud or a flow. The flow and the cloud are very hot and cause a lot of damage to people and areas...

What causes a tsunami?

Tsunami is a large amount of water that moves to the land. An earthquake that occurs in the ocean, as well as a big lake, makes large volumes of water move. A tsunami is often a series of huge waves.

List 3 important differences between P and S waves.

First difference is that P waves are faster than S waves.Secondly, S wave “involves oscillation perpendicular to the direction of propagation,” while P waves are characterized by compressional motion.Thirdly, P waves can travel through liquid, whereas S waves cannot do this.

Discuss the big bang theory and the evidence that supports it. Explain how some scientists regard it as an adequate explanation of the origin of the universe.

The Big Bang theory postulates that the Universe later expanded rapidly. The theory is supported by various pieces of evidence: for instance, the expansion, its early hot state, helium, and galaxy formation are derived from various cosmological models, including cosmic microwave background, Hubble diagram (type la supernovae), availability of light...

The study and analysis of light according to its component wavelengths is called

The answer is spectroscopy. Explanation: Spectroscopy is concerned with the exploration and analysis the electromagnetic spectrum of light. The electromagnetic spectrum is the term used to describe the variety of frequencies of electromagnetic radiation. Different wavelengths of electromagnetic waves produce various colors. Some of these colors can be seen by...