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183_notes:fundamental_principles [2014/11/20 18:20] – created caballero | 183_notes:fundamental_principles [2021/05/11 18:50] (current) – [The Momentum Principle] stumptyl |
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===== The Three Fundamental Principles of Mechanics ===== | ===== The Three Fundamental Principles of Mechanics ===== |
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In this course, you have worked with the 3 central principles to mechanics, [[183_notes:momentum_principle|the momentum principle]], [[183_notes:define_energy#the_first_law_of_thermodynamics_the_energy_principle|the energy principle]], and [[183_notes:l_principle|the angular momentum principle]]. These 3 principles can predict or explain all motion in the universe as we know it. They are incredibly powerful principles that have been tested in many experiments. In this last set of notes, you will be reminded of them. | In this course, you have worked with the 3 central principles to mechanics, [[183_notes:momentum_principle|the momentum principle]], [[183_notes:define_energy#the_first_law_of_thermodynamics_the_energy_principle|the energy principle]], and [[183_notes:l_principle|the angular momentum principle]]. **These 3 principles can predict or explain all motion in the universe as we know it. They are incredibly powerful principles that have been tested in many experiments. In this last set of notes, you will be reminded of them. |
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| ==== Lecture Video ==== |
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| {{youtube>RusrMksTN7g?large}} |
==== The Momentum Principle ==== | ==== The Momentum Principle ==== |
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The momentum principle describes how the momentum of a system will change as a result of external forces. It is a vector principle as it describes how an system will move in three dimensions. | **The momentum principle describes how the momentum of a system will change as a result of external forces.** It is a vector principle as it describes how an system will move in three dimensions. |
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Δ→psys=→FextΔt
| Δ→psys=→FextΔt
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==== The Energy Principle ==== | ==== The Energy Principle ==== |
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The energy principle describes how the energy of a system will change as a result of external work and energy exchange due to a temperature difference. It is a scalar principle as it describes how energy is transferred in and out as well as around a system in different forms. | **The energy principle describes how the energy of a system will change as a result of external work and energy exchange due to a temperature difference.** It is a scalar principle as it describes how energy is transferred in and out as well as around a system in different forms. |
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ΔEsys=W+Q
| ΔEsys=W+Q
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==== The Angular Momentum Principle ==== | ==== The Angular Momentum Principle ==== |
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The angular momentum principle describes how the angular momentum of a system will change as a result of external torques. It is a vector principle as it describes how a system will rotate or translate in 3 dimensions. | **The angular momentum principle describes how the angular momentum of a system will change as a result of external torques.** It is a vector principle as it describes how a system will rotate or translate in 3 dimensions. |
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Δ→Lsys=→τextΔt
| Δ→Lsys=→τextΔt
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