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Rate of force development (RFD) relates to the amount of force that a person can generate over a period of time. More force generated over a time period means that the RFD is higher. Maximum RFD is based upon the greatest amount of force developed in the shortest time.
A high RFD is important in order to achieve faster and more powerful movements. For example, an ability to achieve a higher RFD will mean a person can jump higher than they would be able to do otherwise. The interaction between the neuromuscular system and the muscles is of particular importance in understanding the related physiological processes. [1]
When a fluid flows around an object, the fluid exerts a force on the object. Lift is the component of this force that is perpendicular to the oncoming flow direction. It contrasts with the drag force, which is the component of the force parallel to the flow direction. Lift conventionally acts in an upward direction in order to counter the force of gravity, but it is defined to act perpendicular to the flow and therefore can act in any direction.
Specific impulse is a measure of how efficiently a reaction mass engine, such as a rocket using propellant or a jet engine using fuel, generates thrust. For engines like cold gas thrusters whose reaction mass is only the fuel they carry, specific impulse is exactly proportional to the effective exhaust gas velocity.
Cash flow, in general, refers to payments made into or out of a business, project, or financial product. It can also refer more specifically to a real or virtual movement of money.
Flight or flying is the process by which an object moves through a space without contacting any planetary surface, either within an atmosphere or through the vacuum of outer space. This can be achieved by generating aerodynamic lift associated with gliding or propulsive thrust, aerostatically using buoyancy, or by ballistic movement.
A supercell is a thunderstorm characterized by the presence of a mesocyclone; a deep, persistently rotating updraft. Due to this, these storms are sometimes referred to as rotating thunderstorms. Of the four classifications of thunderstorms, supercells are the overall least common and have the potential to be the most severe. Supercells are often isolated from other thunderstorms, and can dominate the local weather up to 32 kilometres (20 mi) away. They tend to last 2–4 hours.
In railway engineering, the term tractive effort describes the pulling or pushing capability of a locomotive. The published tractive force value for any vehicle may be theoretical—that is, calculated from known or implied mechanical properties—or obtained via testing under controlled conditions. The discussion herein covers the term's usage in mechanical applications in which the final stage of the power transmission system is one or more wheels in frictional contact with a railroad track.
Variable universal life insurance is a type of life insurance that builds a cash value. In a VUL, the cash value can be invested in a wide variety of separate accounts, similar to mutual funds, and the choice of which of the available separate accounts to use is entirely up to the contract owner. The 'variable' component in the name refers to this ability to invest in separate accounts whose values vary—they vary because they are invested in stock and/or bond markets. The 'universal' component in the name refers to the flexibility the owner has in making premium payments. The premiums can vary from nothing in a given month up to maximums defined by the Internal Revenue Code for life insurance. This flexibility is in contrast to whole life insurance that has fixed premium payments that typically cannot be missed without lapsing the policy.
Term life insurance or term assurance is life insurance that provides coverage at a fixed rate of payments for a limited period of time, the relevant term. After that period expires, coverage at the previous rate of premiums is no longer guaranteed and the client must either forgo coverage or potentially obtain further coverage with different payments or conditions. If the life insured dies during the term, the death benefit will be paid to the beneficiary. Term insurance is typically the least expensive way to purchase a substantial death benefit on a coverage amount per premium dollar basis over a specific period of time.
In spaceflight, an orbital maneuver is the use of propulsion systems to change the orbit of a spacecraft. For spacecraft far from Earth an orbital maneuver is called a deep-space maneuver (DSM).
RFD may refer to:
A traction motor is an electric motor used for propulsion of a vehicle, such as locomotives, electric or hydrogen vehicles, or electric multiple unit trains.
The availability factor of a power plant is the amount of time that it is able to produce electricity over a certain period, divided by the amount of the time in the period. Occasions where only partial capacity is available may or may not be deducted. Where they are deducted, the metric is titled equivalent availability factor (EAF). The availability factor should not be confused with the capacity factor. The capacity factor for a given period can never exceed the availability factor for the same period. The difference arises when the plant is run at less than full capacity, in which case the capacity factor is less than the availability factor.
Neutral buoyancy occurs when an object's average density is equal to the density of the fluid in which it is immersed, resulting in the buoyant force balancing the force of gravity that would otherwise cause the object to sink or rise. An object that has neutral buoyancy will neither sink nor rise.
The Reserve Force Decoration is an Australian Military award given for long service by officers of the Reserve Forces. It is part of the suite of defence force service awards introduced in 1982, which also included the Defence Force Service Medal and the Reserve Force Medal. However, the RFD is the only one of the three to carry a postnominal entitlement.
In astronautics, a powered flyby, or Oberth maneuver, is a maneuver in which a spacecraft falls into a gravitational well and then uses its engines to further accelerate as it is falling, thereby achieving additional speed. The resulting maneuver is a more efficient way to gain kinetic energy than applying the same impulse outside of a gravitational well. The gain in efficiency is explained by the Oberth effect, wherein the use of a reaction engine at higher speeds generates a greater change in mechanical energy than its use at lower speeds. In practical terms, this means that the most energy-efficient method for a spacecraft to burn its fuel is at the lowest possible orbital periapsis, when its orbital velocity is greatest. In some cases, it is even worth spending fuel on slowing the spacecraft into a gravity well to take advantage of the efficiencies of the Oberth effect. The maneuver and effect are named after the person who first described them in 1927, Hermann Oberth, a Transylvanian Saxon physicist and a founder of modern rocketry.
Production is the process of combining various inputs, both material and immaterial in order to create output. Ideally this output will be a good or service which has value and contributes to the utility of individuals. The area of economics that focuses on production is called production theory, and it is closely related to the consumption theory of economics.
In capital markets, volume, or trading volume, is the amount of a security that was traded during a given period of time. In the context of a single stock trading on a stock exchange, the volume is commonly reported as the number of shares that changed hands during a given day. The transactions are measured on stocks, bonds, options contracts, futures contracts and commodities.
Certain species of fish and birds are able to locomote in both air and water, two fluid media with very different properties. A fluid is a particular phase of matter that deforms under shear stresses and includes any type of liquid or gas. Because fluids are easily deformable and move in response to applied forces, efficiently locomoting in a fluid medium presents unique challenges. Specific morphological characteristics are therefore required in animal species that primarily depend on fluidic locomotion. Because the properties of air and water are so different, swimming and flying have very disparate morphological requirements. As a result, despite the large diversity of animals that are capable of flight or swimming, only a limited number of these species have mastered the ability to both fly and swim. These species demonstrate distinct morphological and behavioral tradeoffs associated with transitioning from air to water and water to air.
Markstrat is a business market simulation game developed by Jean-Claude Larréché and Professor Hubert Gatignon, in which players take control of a virtual corporation. Players make a number of decisions in marketing, finance, research and development, and other areas in order to achieve a better performance than competing players, who also take control of their own companies. After the game was developed it was distributed on an ad-hoc basis by the French business school INSEAD. Markstrat is played in over 500 academic institutions worldwide, including 8 of the top 10 international business schools.
Power training typically involves exercises which apply the maximum amount of force as fast as possible; on the basis that strength + speed = power. Jumping with weights or throwing weights are two examples of power training exercises. Regular weight training exercises such as the clean and jerk and power clean may also be considered as being power training exercises due to the explosive speed required to complete the lifts. Power training may also involve contrasting exercises such as heavy lifts and plyometrics, known as complex training, in an attempt to combine the maximal lifting exertions with dynamic movements. This combination of a high strength exercise with a high speed exercise may lead to an increased ability to apply power. Power training frequently specifically utilises two physiological processes which increase in conjunction with one another during exercise. These are deep breathing, which results in increased intra-abdominal pressure; and post-activation potentation, which is the enhanced activation of the nervous system and increased muscle fibre recruitment. Power training programmes may be shaped to increase the trainee's ability to apply power in general, to meet sports specific criteria, or both.
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