Fourier’s law of thermal conduction helps us in quantifying heat transfer processes using appropriate rate equations. According to Fourier’s law of thermal conduction, the time rate of heat transfer through a material is proportional to the negative gradient in temperature and area. Its differential form is: q = − k ▽ T Where: Fourier’s Law …
Energy
A dam forms a large reservoir of water with a large elevation difference. The difference in elevation between the water behind the dam and the river downstream generates potential energy, which can be converted to mechanical energy by rotating turbines. Hydroelectric turbines spin like a carousel around a vertical axis to spin magnets within an …
Secondary energy sources, also known as energy carriers, are generated by transforming primary energy sources like solar, wind and hydro energy. They transmit usable energy from one point to another. Common examples of secondary energy sources are petrol, hydrogen and electricity. Primary energy resources are those found in nature. They include fossil fuels (petroleum, natural …
The Helmholtz free energy is a thermodynamic potential defined in thermodynamics as the internal energy minus the product of temperature times entropy. It quantifies the “useful” work produced by a closed thermodynamic system at constant volume and pressure. Helmholtz free energy is defined as follows: F = U – TSdF = -SdT – pdV Internal …
A thermochemical calorie (small calorie) is the amount of energy required to heat one gramme of water by one degree Celsius. Its British Imperial equivalent, the BTU, is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. Moreover, we have to distinguish between a small …
Electricity is generated in power plants that can harvest electrical energy from primary energy sources. Primary energy sources could be renewable (wind, solar power, tidal power, etc.) or non-renewable (coal, natural gas, oil, etc.). Fossil fuels like coal are turned into electricity by burning them to make steam to turn a turbine; unfortunately, this makes …
Green energy is defined as energy derived from renewable sources. Solar energy from the sun, geothermal energy from heat within the earth, wind energy, biomass from plants, and hydropower from flowing water are the primary renewable energy sources. Green energy got its name because its production emits no toxic greenhouse gases into the atmosphere, resulting …
Energy is defined as the ability to perform work. Energy comes in a variety of forms. Here are some examples of common energy types. 1. Thermal Energy Thermal energy is the energy produced by heat. It is the kinetic energy associated with the random movement of molecules in a material. The kinetic energy of molecules …
The photoelectric effect is a phenomenon that occurs when light strikes a metallic surface and causes electrons to eject from it. The electrons emitted in this process are photoelectrons. Alkali metals are commonly used in the photoelectric emission process. These are lithium, sodium, potassium, rubidium, and cesium, which exhibit a photoelectric effect when exposed to …
The electric power formula is given by P = VI, where V is the potential difference, I is the electric current and P is the electric power. Power is the rate at which energy of any type is transferred; electric power is the rate at which electric energy is transferred in a circuit. In the SI system, …
Einstein’s mass-energy equivalence formula (E = mc²), also known as the mass-energy equivalence, is one of his most famous contributions. It is a well-known equation in physics and mathematics that shows what happens when mass is converted to energy or energy is converted to mass. Einstein’s equation is expressed quantitatively as: E = mc2 According to Einstein’s …
The binding energy is the amount of energy needed to disassemble or separate a nucleus into its constituent nucleons. The protons, neutrons, and other nuclear particles that make up the nucleus of any atom are referred to as nucleons. The nucleons are held together by forces known as strong nuclear forces, and the stronger the …
Rotational kinetic energy, also known as rotational kinetic energy, is the energy that an object has while rotating. Rotational kinetic energy is associated with rotational motion and is a component of an object’s total kinetic energy. The rotational kinetic energy of an object is equal to one-half the product of its moment of Inertia, I, and …
A biofuel is any type of fuel derived from the process of biological carbon fixation. Biological carbon fixation occurs in living organisms. The primary distinction between a biofuel and a fossil fuel is the time span over which the fixation occurs. Fixation in a biofuel takes months or years as compared to fossil fuels where Fixation …
Aerobic respiration, which uses oxygen, and anaerobic respiration, which does not use oxygen, are two types of cellular respiration. Although some cells use only one type of respiration, most cells use both types depending on the needs of the organism. Cellular respiration occurs outside of macroorganisms as chemical processes, such as fermentation. In general, respiration …