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How Much Electricity do Appliances Use

postman1 — Sat, 03 Sep 2011 10:39:23 +0000

Household appliances use a varied amount of electricity, depending on their efficiency. Location of an appliance can affect electricity usage. For example, a clothes dryer in an open location like a garage, is likely to be somewhat less efficient than one located in a house. Similarly, a water heater with improper insulation is likely to be less efficient and will use more electricity than a well-located and insulated water heater.

Another factor affecting electricity usage of an appliance is the age of the appliance. If your refrigerator is forty years old, chances are your electricity bills are quite high. If you have purchased a refrigerator in the US within the last five years, you are likely to have a far more energy efficient appliance, which represents significant savings on your electricity bill. Today, more and more appliances in the US are now given the Energy Star seal of approval, which guarantees less usage of electricity.

Electricity in the US is measured in kilowatts. A kilowatt costs about .06 US dollars (USD) per hour. Rates can be different depending upon where you live, and on your total electricity usage for the month. Rates vary, and increase with higher energy usage

The average freezer and refrigerator purchased before 1985 uses about 100 kilowatt hours per month. This means you will pay approximately 6 USD per month to run a refrigerator. A refrigerator purchased after the year 2000 only uses only about 37.5 kilowatt hours per month, representing a huge savings on your electricity bills. This is the average measurement for a relatively small fridge. Larger refrigerators will use far more electricity.

Relatively new washing machines use about 360 kilowatt hours per year. Relatively new dryers use approximately 765 kilowatt hours per year. Your electric bill will usually specify exactly how many cents you are charged per kilowatt hour, which can help you determine the cost of running an appliance.

Small appliances or household electrics can often use a surprising number of kilowatt hours. A computer and monitor without sleep mode can use up over 400 kilowatt hours per year. A standing fan may use twice that.

However, large appliances like air conditioners are some of the worst consumers of electricity. Central air conditioning may use as much as 2000 kilowatt hours per year, and sometimes more. Electric furnaces are the most expensive however, using over 6000 kilowatt hours per year.

Most appliances today are now labeled with their average rate of usage, and of course, kilowatt usage can depend upon how much you use an appliance. If you rarely turn on an electric furnace, you’re not likely to use much electricity. Keeping appliances clean, and turning off appliances when not in use, like the TV or computer, can mean a little less money paid to the company supplying your electricity.

With electricity supply sometimes being exceeded by demand in heavily populated areas, it makes sense to choose appliances that will use the least amount of electricity possible

How Many Elements on the Periodic Table of the Elements Occur Naturally

postman1 — Sun, 24 Apr 2011 16:29:14 +0000

The answer to the question of how many objects on the periodic table of the elements are naturally occurring is actually a bit complicated. Conventional wisdom says that the first 92 elements, from element one, hydrogen, to element 92, uranium, are all naturally occurring, but in fact some of these elements are highly unstable, and have only been observed when they have been created artificially. Some people believe that elements 93 (neptunium) and 94 (plutonium) should also be included on a list of naturally occurring elements. As a result, anywhere between 94 and 88 elements are “naturally occurring,” depending on the definition one is using.
Elements are considered to be “naturally occurring” when they can be found in nature, rather than needing to be created in a laboratory, and many representations of the periodic table of the elements include a dividing line between natural and artificially produced elements. Some naturally occurring elements have very unstable isotopes or short half-lives, so they exist only intermittently and in very small quantities on Earth. Some people believe that when thinking about the periodic table of the elements, elements such as these should not really be considered “naturally occurring,” especially since they are only observed as a direct result of human activity. Others argue that while only small amounts are observable at any given time, they are “natural” because they can occur spontaneously.
The questionable elements are: element 43, technetium; element 61, promethium; element 85, astatine; and element 87, francium. Elements 43 and 61 are somewhat unusual, as they are surrounded by stable elements, but they have only been observed in controlled laboratory conditions. Elements 85 and 87 do appear in nature, but only briefly, and very rarely, making it tough to pin down an actual natural appearance for these shy members of the periodic table of the elements.
If all four questionable elements are struck from the list of “naturally occurring” elements, you end up with either 90 or 88 naturally occurring elements, depending on whether or not you think neptunium and plutonium belong on the list. Some people include astatine and francium on the list of naturally occurring elements, raising the total to 92 or 90. The most-commonly cited number is “92,” which could be viewed as the first 92 entries on the periodic table of the elements, or the first 94 minus elements 43 and 61, depending on how complicated you feel like being.
It it is important to remember that when looking at the periodic table of the elements, “naturally occurring” does not necessarily mean “abundant.” Many naturally occurring elements are in fact quite rare, although some were once more abundant. Levels of elements also change depending on where you are: helium, for example, is rare on Earth, but abundant around the Sun.

How Much do Wind Turbines Cost

postman1 — Thu, 21 Apr 2011 19:52:17 +0000

Total costs for installing a commercial-scale wind turbine will vary significantly depending on the cost of financing, when the turbine purchase agreement was executed, construction contracts, the type of machine, the location of the project, and other factors. Cost components for wind projects include wind resource assessment and site analysis expenses; the price and freight of the turbine and tower; construction expenses; permitting and interconnection studies; utility system upgrades, transformers, protection, and metering equipment; insurance; operations, warranty, maintenance, and repair; legal and consultation fees. Others factors that will impact your project economics include your financing costs, the size of your project, and taxes.
The costs for a commercial scale wind turbine in 2007 ranged from $1.2 million to $2.6 million, per MW of nameplate capacity installed.
Most of the commercial-scale turbines installed today are 2 MW in size and cost roughly $3.5 Million installed. Wind turbines have significant economies of scale. Smaller farm or residential scale turbines cost less overall, but are more expensive per kilowatt of energy producing capacity. Wind turbines under 100 kilowatts cost roughly $3,000 to $5,000 per kilowatt of capacity. That means a 10 kilowatt machine (the size needed to power an average home) might cost $35,000-$50,000.

How Many Yards Of Sand In a Ton

postman1 — Thu, 21 Apr 2011 13:24:43 +0000

A cubic yard is a measure of volume (length in feet X width in feet X depth in feet/27=cubic yards) and tons is a measure of weight. The weight of a material depends on its density, therefore, to determine the number of yards in a ton of material, the density of the material must be known.

Sand has an average weight of 2,700 pounds per cubic yard (Refer to Table 1 in this chart of material weights http://www.age.psu.edu/extension/factsheets/h/H20.pdf). One ton is 2,000 pounds, therefore, there are 1.35 Tons in one cubic yard of sand.

Inversely, if 1.35 tons of sand is equivalent to one cubic yard of sand, then using a ratio (tons|cubic yards), there are 0.74 cubic yards in one ton of sand.

For those of you that prefer to see this answer as a mathematical calculation:

length in feet X width in feet X depth in feet/27=cubic yards
Sand = 2,700 lbs/cubic yards (*This value is specific to Sand)

*2,700 lbs|1 Cu Yd * 1 Ton|2,000 lbs = 1.35 Ton|Cu Yd
OR 1|1.35 = 0.74074 Cu Yd in 1 Ton of Sand

How Much Does Sea Water Weigh Per Cubic Foot

postman1 — Thu, 21 Apr 2011 13:05:24 +0000

The weight of sea water really depends on a number of variables, including the temperature, the amount of salt (salinity) and whatever other foreign items may be present, and the depth, thus the pressure.
But to get to the basic answer, seawater, at the surface, on average weighs 1027 kg/m3, or just over 64.1 lbs per cubic foot.

How Many Chemical Elements Are There

postman1 — Sun, 07 Feb 2010 19:39:29 +0000

How Many Chemical Elements are There?

A chemical element is a type of atom, like hydrogen or oxygen. As of January 2007, 117 elements have been observed, with 94 of these elements occurring naturally on Earth. 23 elements are artificially created, in nuclear reactors or particle accelerator experiments. The first synthetic element to be created in substantial quantities was plutonium, element 94. Plutonium is also the heaviest atom found naturally on Earth. With a half-life of only 80 million years, plutonium occurs in extremely small quantities in uranium ores.

The present-day chemical elements come from one of three sources: supernova nucleosynthesis, stellar nucleosynthesis, and Big Bang nucleosynthesis. Nucleosynthesis occurs when atomic nuclei pressed together so closely and at such high heat that they overcome the mutual repulsion of their electron shells and produce heavier nuclei. In this way, hydrogen nuclei can be fused into helium nuclei, which can in turn fuse into carbon nuclei, if conditions of sufficient temperature and pressure are reached.

At the beginning, the universe was so hot and dense that it consisted of nothing but free quarks — the constituents of protons and neutrons — electrons, and radiation. After a millionth of a second, quarks began to fuse into baryons: protons and neutrons. For the first twenty minutes after the Big Bang, the temperature of the universe exceeded that in the center of the brightest stars, with a density greater than air. During this period, protons and neutrons collided energetically to form larger nuclei: deuterium and two isotopes of helium. 25% of all the matter in the universe was converted into helium, with about 75% hydrogen, along with trace amounts of heavier elements such as lithium. This is similar to the current-day ratio of chemical elements.

The first stars formed about 300 million years after the Big Bang, initiating another form of nucleosynthesis called stellar nucleosynthesis. In stellar nucleosynthesis, greatly compacted matter in the center of a star undergoes nuclear fusion, releasing large amounts of energy and balancing out the forces of gravity acting to collapse the star. This can be thought of as a continuously exploding H-bomb. Elements up to iron on the Periodic Table are formed in stellar nucleosynthesis.

To create elements heavier than iron requires another type of nucleosythesis, supernova nucleosynthesis. Supernovae occur when stars collapse catastrophically after consuming all their nuclear fuel in their cores. The atmospheric envelope of the star collapses inward due to gravity, bouncing off a core made of nearly-incompressible “electron degenerate” matter. During this abrupt bounce, several percent of the star’s material is fused into heavier elements nearly instantaneously. This releases enough energy for the supernova to outshine its host galaxy for days or weeks. Elements heavier than iron are synthesized during this incredibly energetic cosmic event.

How Much Uranium Is In the Solar System

postman1 — Tue, 19 Jan 2010 22:46:31 +0000

How Much Uranium is in the Solar System ?

We don’t know the composition of the asteroids or the objects in the Oort comet cloud or the Kuiper belt in great detail. One theory of solar system formation is that there are more metals in the inner solar system. That would mean most of the uranium is Mars, Mercury, Earth Venus and asteroid belt. There is an estimated 40 trillion tons of Uranium and 120 trillion tons of thorium in the Earth’s crust. Most of that Uranium is concentrated in the continental crust. The mantel has lower concentration of uranium, but there is a lot more mantel and mantel recycles out to crust.

The solar heavy-element abundances described above are typically measured both using spectroscopy of the Sun’s photosphere and by measuring abundances in meteorites that have never been heated to melting temperatures. These meteorites are thought to retain the composition of the protostellar Sun and thus not affected by settling of heavy elements. The two methods generally agree well.

Meteors tend to only have 0.008 ppm uranium. The Sun is 332,830 earth masses. So if the Sun was 8 ppb (parts per billion) uranium, then 0.27% of an earth mass of uranium in the Sun.

How Many Molecules of Water Are in a Single Drop

admin — Tue, 19 Jan 2010 11:06:15 +0000

How many molecules of water are in a single drop?

The simplest way is to know two things about the object:
1) Its chemical composition.
2) Its mass.
As an example, let’s say we have a very tiny drop of water, say 1 microliter, which would have a mass of 0.001 grams. The chemical formula for water is H₂O which means that every molecule of water has 2 atoms of hydrogen (H) and one atom of oxygen (O). From the Periodic Table of Elements, one sees that one mole of hydrogen atoms weighs 1 gram while one mole of oxygen atoms weighs 16 grams.

A mole is a convenient counting unit whenever one is dealing with numbers of atoms or molecules. It is equal to Avogadro’s number (NA), namely 6.022 x10²³. If we have one mole of water, then we know that it will have a mass of 2 grams (for 2 moles of H atoms) + 16 grams (for one mole O atom) = 18 grams. Since we only have 0.001 grams, that means that we have NA * (0.001/18) = 3.35*10¹⁹ molecules of water! This is a huge number, even though we only started with a tiny amount of water.

How Much Does Planet Earth Weigh

admin — Mon, 11 Jan 2010 18:07:51 +0000

How much does planet Earth weigh?

It would be more proper to ask, “What is the mass of planet Earth?”¹ The quick answer to that is: approximately 6,000,000,000,000 ,000,000,000,000 (6E+24) kilograms.

The interesting sub-question is, “How did anyone figure that out?” It’s not like the planet steps onto the scale each morning before it takes a shower. The measurement of the planet’s weight is derived from the gravitational attraction that the Earth has for objects near it

It turns out that any two masses have a gravitational attraction for one another. If you put two bowling balls near each other, they will attract one another gravitationally. The attraction is extremely slight, but if your instruments are sensitive enough you can measure the gravitational attraction that two bowling balls have on one another. From that measurement, you could determine the mass of the two objects. The same is true for two golf balls, but the attraction is even slighter because the amount of gravitational force depends on mass of the objects.

Newton showed that, for spherical objects, you can make the simplifying assumption that all of the object’s mass is concentrated at the center of the sphere. The following equation expresses the gravitational attraction that two spherical objects have on one another:

F = G * M1 * M2 / R²

R is the distance separating the two objects.
G is a constant that is 6.67259×10^-11m³/s² kg.
M1 and M2 are the two masses that are attracting each other.
F is the force of attraction between them.

Assume that Earth is one of the masses (M1) and a 1-kg sphere is the other (M2). The force between them is 9.8 kg*m/s² — we can calculate this force by dropping the 1-kg sphere and measuring the acceleration that the Earth’s gravitational field applies to it (9.8 m/s²).

The radius of the Earth is 6,400,000 meters (6,999,125 yards). If you plug all of these values in and solve for M1, you find that the mass of the Earth is 6,000,000,000,000,000,000,000,000 kilograms (6E+24 kilograms / 1.3E+25 pounds).

¹ It is “more proper” to ask about mass rather than weight because weight is a force that requires a gravitational field to determine. You can take a bowling ball and weigh it on the Earth and on the moon. The weight on the moon will be one-sixth that on the Earth, but the amount of mass is the same in both places. To weigh the Earth, we would need to know in which object’s gravitational field we want to calculate the weight. The mass of the Earth, on the other hand, is a constant.

How Many Kilometers Are In The Speed of Light

admin — Mon, 11 Jan 2010 17:36:24 +0000

How many kilometers are in the speed of light?

The speed of light (usually denoted c) is a physical constant. Its value is exactly 299,792,458 metres per second, often approximated as 300,000 kilometres per second or 186,000 miles per second. It is the speed of electromagnetic radiation (such as radio waves, visible light, or gamma rays) in vacuum, where there are no atoms, molecules or other types of matter that can slow it down.
For much of human history, it was not known whether light was transmitted instantaneously or simply very quickly. In the 17th century, Ole Rømer first demonstrated that it travelled at a finite speed by studying the apparent motion of Jupiter’s moon Io. By 1975, the speed of light was known to be 299,792,458 m/s with a relative measurement uncertainty of 4 parts per billion. In 1983, the metre was redefined in the International System of Units (SI) as the distance travelled by light in vacuum in 1⁄299,792,458 of a second. As a result, the numerical value of c in meters per second is now fixed exactly by the definition of the meter.
According to the theory of special relativity, c connects space and time in the unified structure of space-time, and its square is the constant of proportionality between mass and energy (E = mc2). In any inertial frame of reference, independently of the relative velocity of the emitter and the observer, c is the speed of all massless particles and associated fields, including all electromagnetic radiation in free space, and it is believed to be the speed of gravity and of gravitational waves. It is an upper bound on the speed at which energy, matter, and information can travel, as surpassing it would be equivalent to travelling backwards in time. Its finite value is a limiting factor in the speed of operation of electronic devices.
The actual speed at which light propagates through transparent materials, such as glass or air, is less than c. The ratio between c and the speed v at which light travels in a material is called the refractive index n of the material (n = c / v). For example, for visible light the refractive index of glass is typically around 1.5, meaning that light in glass travels at c / 1.5 ≈ 200,000 km/s; the refractive index of air for visible light is about 1.0003, so the speed of light in air is very close to c.