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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.
The balloon is filled with air on the ground where the pressure is 1bar. When the balloon goes higher, the pressure outside it becomes lower since there is significantly less air. Thus, the pressure inside the balloon becomes higher than that outside it. The difference in pressure results in an...
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...
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...
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...
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...
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...
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...
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...
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,...
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...
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...
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...
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).
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,...
Clamp sensors can be used for measurements after placement on arms and ankles. For frequencies that may be less than 100 MHz, contact or current meters are appropriate. They estimate the current flow of an earthed human who may be in contact with the concerned conductor. Broadband radio receivers can...
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:...
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....
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...
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...
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...
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.
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...
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,...
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...
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...
Stars are the most glittering objects in the night sky. It is really an interesting subject to know about the stars and astronomers rely upon different methods to understand all the important things about the stars. A star is a massive and luminous plasmatic ball and all the plasma is...
The stars which occupy the region near the line in the Hertzsprung-Russell diagram are called the main sequence of the stars. This is the stage where the stars are fusing hydrogen in the core of their system. The next concentration of stars in the diagram is known as the horizontal...
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...
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...
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...
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...
The measure of inertia, which depends on mass and not weight or gravity, is a resistance offered by a body to change in position or motion. In a state of rest, the mass of an object is its measure of inertia. When a body is in motion, inertia is proportional...
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...
The universe is 14 billion years old. Over these years of development, several cosmological phenomena and forces have shaped the current state of the universe. In order to predict possible future scenarios of the cosmos, it would be pertinent to understand its current and past state. It’s only in its...
The Big Bang Theory is the most widely accepted cosmological model that seeks to explain the development of the universe. In the beginning, considerable energies became concentrated at one place, thereby producing a reactionary expansion that caused a big explosion now known as the Big Bang. This model explains that...
The Milky Way galaxy, which contains Earth, is not a radio galaxy since it does not emit light at radio wavelengths. However, some traces of radiation are still detectable emanating from its center. Scalzi reiterates that many peculiar galaxies are sources of radio emission. Even a “normal” galaxy like our...
Quasars are luminous galaxies that emit radio waves in the spectrum between 10 MHz and 100 GHz, making them detectable as red flashes of light. They are thousands of light-years away from our own galaxy and form the core part of most distant galaxies. The evidence is now overwhelming that...
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...
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...
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...
Cooler object tends to give out more radiations of higher wavelengths then hotter ones. Determining the position at which the spectrum peaks will determine its temperature. Since each element gives out or absorbs light of a particular wavelength, by analyzing the light spectrum of the star, we can figure out...
The Sun is the primary source of energy for most living things on earth. It is also the primary source of energy for wind power, producing a flow of air by causing temperature differences in parts of the earth surface. The primary source of tidal power, however, is the moon...
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...
The annual solar radiation at the surface of the earth is over 10000 time’s primary global energy consumption. Large solar plants can be used to produce electricity cheaply. Photovoltaic cells can be installed on buildings to produce clean energy on individual basis. Advantages of solar energy as compare to fossil...
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...
The popular method that is being used is called the parallax. Due to the earth’s revolution around the sun, stars that are close by earth also seem to be very distant. Thus, astronomers, by having prior knowledge of the movement of stars and the earth’s orbit, are able to calculate...
Stellar evolution could be said to be a process by which a star goes through a series of major changes during its lifetime. This would vary from a few million years (for greater mass) to trillion years (for lesser masses) depending upon the mass of the stars. During the lifetime...
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...
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...
Some of the gas-dust clouds are so dense that they begin to contract under the influence of their own gravity. According to Drake et al., as the compression increases, the density and temperature of the cloud increase, and it begins to emit abundantly in the infrared spectral range, forming a...
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...
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...
Solar energy is an inexhaustible and safe source of power. However, some negative factors of the influence of the star’s activity on the Earth and its inhabitants can be manifested. In particular, these are magnetic storms that can affect people’s health, glacial periods that occurred on the earth many thousands...
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....
The Milky Way is studied in more detail than Andromeda. As for both galaxies, astronomers know the approximate number of stars and geometric dimensions. The future of these two galaxies is not very encouraging. The Andromeda galaxy is moving slowly towards the Milky Way. The Milky Way will collide with...
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...
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,...
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...
The caskets with the bodies of the three deceased employees were covered with lead and a thick layer of concrete in order to reduce the radiation background in the burial area due to an extremely long half-life of the isotope uranium-235.
A fission reaction is a nuclear fusion process aimed at generating energy. To absorb a neutron, a special isotope, uranium-235, is applied.
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.
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...
The content of silica in magma affects its viscosity. Thus, if the content of silica increases viscosity of magma also becomes higher. This process is associated with the high melting point of this compound.
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.
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.
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...
Stellar Parallax describes the movement of a star against other more distant stars during the revolution of the Earth around the Sun. The concept can be used to determine the distance of a few stars that are close to the Sun. Mathematically, the distance to a star in parsecs will...
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...
The correct answer is C. An incandescent light bulb produces a continuous visible spectrum. Explanation: Visible light spectrum is the term used to define the range of wavelength that can be discerned by the human eye. However, the vast share of electromagnetic waves are invisible to humans. Below is the...
Correct answer is B. A real object has a positive object distance. Explanation: The lens equation is an important topic in physics and optics because it allows quantifying the relationship between an object and an image. There are three key concepts involved in a lens equation: object distance, image distance,...