Total Harmonic Distortion (THD) is a measured difference in audio levels between the input audio signal’s harmonics and the harmonics of the output audio signal of an amplifier or other audio device. Output Distortion Level As the signal passes through an amplifier it is always somewhat distorted at its output. The waveform at the input will not perfectly match the level at the output. How great the distortion will be depends on the amplifier’s quality and specifications, but it is usually not noticeable to the human ear. If it is, Read More

In the world of ice hockey and ice skating, there is nothing more important than maintenance of the ice. Failure to properly take care of an ice rink could result in broken bones, property damage, or the loss of a game. In order to efficiently care for an ice rink, ice rink owners spend large sums of money for a machine known as a Zamboni that is able to shave the ice, collect the ice shavings, wash the ice, and resurface the ice with a fresh layer of water. This Read More

Adding exponents is one of the three basic rules when dealing with the combination of two bases and powers. The general rule for it is as followed: when you want to multiply the powers with the same base, simply add the two exponents together. In other words, if the bases are the same number, to multiply the two together, simply add the two exponents together to gain the right answer. Before that can be done, though, it is important to understand what a base and exponent are. What are Bases Read More

The law of universal gravitation gives the attraction force between two objects due to gravity. Definition: For any pair of objects, they attract each other with a force that is directly proportional to the product of the masses of the objects and inversely proportional to the square of the distance between their centers of mass. Gravitational constant (G): the proportionality constant is known as gravitational constant, it is a positive number and its value is about 6.67 x 10-11 N m2 kg-2. Center of Mass: For a homogenous sphere the Read More

A plasma cutter is a device that directs an ionized gas at an object under extreme temperatures. Plasma cutters are often used for industrial purposes, such as cutting metal, and are dependent on plasma, an extremely hot state of matter. Plasma cutters are essentially a type of plasma torch meant for cutting metal rather than welding it. How Plasma Cutters Work A plasma cutter is comprised of one or more gas tanks, a negatively charged electrode, and a number of channels or internal hoses. As oxygen, nitrogen, or another gas Read More

A combustible gas detector is a device that allows the user to detect and analyze any nearby concentrations of combustible gases. Combustible gases are simply gases that will catch on fire when mixed with oxygen and ignited. There are many different types of combustible gases and each one requires its own method of analysis. Some gases are lighter than air while other gases or heavier. This means that each gas has its own level of concentration that it must meet before it can combust. Because of this, combustible gas detectors Read More

The Dow Chemical Company has the trademark for Styrofoam, a foam made from extruded polystyrene. The extruded polystyrene is made from styrene. Styrofoam has been used in many ways since it was first invented in 1941. It has low density and does not conduct heat well due to the large pockets of air in its structure. Styrofoam is commonly used to insulate panels, act as impact-absorbing inserts in automobiles, and in gasket materials. Who Discovered Polystyrene? Although Dow has the Styrofoam trademark, Eduard Simon is credited with discovering polystyrene in Read More

Most hybrid cars use a combination of gasoline and electric engines. There are also types of hybrid cars that use a combination of diesel and electric engines. Gasoline & Electric -Powered Cars ‘Regular’ gasoline-powered cars derive their propulsion power from combustion of gasoline. The combustion of gas produces the energy needed to turn the transmission as well as the wheels. Unfortunately, although fossil fuels still delivers the most power per pound, their by-products are harmful to the environment. Fossil fuels are also non-renewable resources and they are becoming more and Read More

Kinetic energy is the energy of motion. It is also referred to as energy in motion, or as the work required to take an object from being at rest to action/movement. Mathematically, kinetic energy is calculated as ½ of the mass of a body, multiplied by the speed of the body squared, KE=1/2 mv^2. Where Did the Kinetic Energy Term Originate? The term originated with the Greek words kinesis (motion) and energeia (active work). Put together, the two words translate to “Through motion do active work.” More simply, any thing, Read More

Ion propulsion refers to a method of space travel in which accelerating ions, rather than traditional chemical rockets, speed up a spacecraft. While ion propulsion produces very little thrust in comparison to chemical propulsion, it produces consistent acceleration that allows the spacecraft to eventually travel faster than a chemical rocket would. Ion propulsion requires an environment with no radical ions, which means that it cannot be used for air travel, and only works well in interplanetary travel due to its exponential acceleration. Ion propulsion also requires a rather large amount Read More