mechanical advantage
(noun)
In a simple machine, the ratio of the output force to the input force.
Examples of mechanical advantage in the following topics:
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Simple Machines
- They can be described as the simplest mechanisms that use mechanical advantage (or leverage) to multiply force.
- The ratio of the output force to the input force is the mechanical advantage of the machine.
- If the machine does not absorb energy, its mechanical advantage can be calculated from the machine's geometry.
- For instance, the mechanical advantage of a lever is equal to the ratio of its lever arms.
- Describes the following terms as they relate to simple machine; input force, output force, input distance, output distance, mechanical advantage.
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Muscles and Joints
- The reason is clear, since most muscles are attached to bones via tendons close to joints, causing these systems to have mechanical advantages much less than one.
- An approximately equivalent mechanical system with the pivot at the elbow joint
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Convection
- Similarly, the gap between the two panes of a double-paned window is about 1 cm, which prevents convection and takes advantage of air's low conductivity to prevent greater loss.
- Fur, fiber and fiberglass also take advantage of the low conductivity of air by trapping it in spaces too small to support convection.
- Such a mechanism is called positive feedback, since the process reinforces and accelerates itself.
- These systems sometimes produce violent storms with lightning and hail, and constitute the mechanism that drives hurricanes.
- The rise of clouds is driven by a positive feedback mechanism.
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Implications of Quantum Mechanics
- The field of quantum mechanics has been enormously successful in explaining many of the features of our world.
- Quantum mechanics has also strongly influenced string theory.
- The application of quantum mechanics to chemistry is known as quantum chemistry.
- Relativistic quantum mechanics can, in principle, mathematically describe most of chemistry.
- Explain importance of quantum mechanics for technology and other branches of science
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Conservation of Mechanical Energy
- Conservation of mechanical energy states that the mechanical energy of an isolated system remains constant without friction.
- Conservation of mechanical energy states that the mechanical energy of an isolated system remains constant in time, as long as the system is free of all frictional forces.
- This equation is a form of the work-energy theorem for conservative forces; it is known as the conservation of mechanical energy principle.
- The total kinetic plus potential energy of a system is defined to be its mechanical energy (KE+PE).
- An example of a mechanical system: A satellite is orbiting the Earth only influenced by the conservative gravitational force and the mechanical energy is therefore conserved.
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Work
- Work performed by a closed system is the energy transferred to another system that is measured by mechanical constraints on the system.
- In thermodynamics, work performed by a closed system is the energy transferred to another system that is measured by mechanical constraints on the system .
- Thermodynamic work encompasses mechanical work (gas expansion, ) plus many other types of work, such as electrical.
- As such, thermodynamic work is a generalization of the concept of mechanical work in mechanics.
- Analyze the necessity to exclude energy transferred between system as heat from mechanical work
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Philosophical Implications
- Since its inception, many counter-intuitive aspects of quantum mechanics have provoked strong philosophical debates.
- This is due to the quantum mechanical principle of wave function collapse.
- One of the most bizarre aspect of the quantum mechanics is known as quantum entanglement.
- According to the Copenhagen interpretation of quantum mechanics, their shared state is indefinite until measured.
- Formulate the Copenhagen interpretation of the probabilistic nature of quantum mechanics
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A Physical Aside: Einstein coefficients
- Fermi's Golden Rule relates the cross-section for a process to a quantum mechanical matrix element and the phase space available for the products.
- Because quantum mechanics for the most part is time reversible, the cross-section for the forward and reverse reactions are related.
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The Wave Function
- A wave function is a probability amplitude in quantum mechanics that describes the quantum state of a particle and how it behaves.
- In quantum mechanics, a wave function is a probability amplitude describing the quantum state of a particle and how it behaves.
- The laws of quantum mechanics (the Schrödinger equation) describe how the wave function evolves over time.
- This figure shows some trajectories of a harmonic oscillator (a ball attached to a spring) in classical mechanics (A-B) and quantum mechanics (C-H).
- In quantum mechanics (C-H), the ball has a wave function, which is shown with its real part in blue and its imaginary part in red.
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Mechanical Work and Electrical Energy
- Mechanical work done by an external force to produce motional EMF is converted to heat energy; energy is conserved in the process.
- Therefore, we conclude that the mechanical work done by an external force to keep the rod moving at a constant speed is converted to heat energy in the loop.
- More generally, mechanical work done by an external force to produce motional EMF is converted to heat energy.
- Apply the law of conservation of energy to describe the production motional electromotive force with mechanical work