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尋求物理英文翻譯高手

Problem-Solving Strategy, 3

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Analyze: Identify the configuration for zero potential energy

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Include both gravitational and elastic potential energies

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If more than one force is acting within the system, write an expression for the potential energy associated with each force

Problem-Solving Strategy, 4

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If friction or air resistance is present, mechanical energy of the system is not conserved

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Use energy with non-conservative forces instead

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The difference between initial and final energies equals the energy transformed to or from internal energy by the nonconservative forces

Problem-Solving Strategy, 5

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If the mechanical energy of the system is conserved, write the total energy as

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Ei= Ki+ Uifor the initial configuration

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Ef= Kf+ Uffor the final configuration

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Since mechanical energy is conserved, Ei= Ef and you can solve for the unknown quantity

Mechanical Energy and Nonconservative Forces

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In general, if friction is acting in a system:

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ΔEmech= ΔK+ ΔU= -ƒkd

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ΔU is the change in all forms of potential energy

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If friction is zero, this equation becomes the same as Conservation of Mechanical Energy

Nonconservative Forces, Example 1 (Slide)

ΔEmech = ΔK + ΔU

ΔEmech =(Kf – Ki ) +

(Uf – Ui )

ΔEmech = (Kf + Uf ) –

(Ki + Ui )

ΔEmech = 1/2 mvf平方 – mgh = -ƒk d

Nonconservative Forces, Example 2 (Spring-Mass)

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Without friction, the energy continues to be transformed between kinetic and elastic potential energies and the total energy remains the same

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If friction is present, the energy decreases

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ΔEmech= -ƒkd

2 個解答

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最佳解答

Problem-Solving Strategy, 3

解題策略3����

Analyze: Identify the configuration for zero potential energy Include both gravitational and elastic potential energies

分析：識別重力位能和彈力位能兩者的零位能型態����

If more than one force is acting within the system, write an expression for the potential energy associated with each force

當不只一個力作用在系統中時，描述各個力結合後的位能

Problem-Solving Strategy, 4

解題策略4����

If friction or air resistance is present, mechanical energy of the system is not conserved

當磨擦力或空氣阻力出現時，系統的機械能是非守衡的，����

Use energy with non-conservative forces instead

用非守恆力的能量代換����

The difference between initial and final energies equals the energy transformed to or from internal energy by the nonconservative forces

初能量與末能量的差等於由非守恆力所轉換至內部由內部轉換出來的能量

Problem-Solving Strategy, 5

解題策略5����

If the mechanical energy of the system is conserved, write the total energy as

Ei= Ki+ Ui for the initial configuration

如果系統的機械能是守恆的，列出初型態時的總能量如下式����

���� Ei＝Ki+ Ui

Ef= Kf+ Uf for the final configuration

末型態時的總能量���� Ef＝Kf+ Uf

Since mechanical energy is conserved, Ei= Ef and you can solve for the unknown quantity

由於機械能是守恆的，由 Ef＝Uf可求得未知量

Mechanical Energy and Nonconservative Forces

機械能與非守恆力����

In general, if friction is acting in a system:

通常如果有摩擦力作用於系統上����

ΔEmech= ΔK+ ΔU= -ƒkd

ΔU is the change in all forms of potential energy

ΔU 為所有型態的位能變化����

If friction is zero, this equation becomes the same as Conservation of Mechanical Energy

如果磨擦力為零，本方程式就變得跟機械能守恆時相同

Nonconservative Forces, Example 1 (Slide)

非守恆力舉例(見幻燈片)

ΔEmech = ΔK + ΔU 機械能變化＝動能變化＋位能變化

ΔEmech =(Kf – Ki ) + (Uf – Ui )

機械能變化＝(末動能－初動能)＋(末位能－初位能)

ΔEmech = (Kf + Uf ) –(Ki + Ui )

機械能變化＝(末動能＋末位能) －(初動能＋初位能)

ΔEmech = 1/2 mvf平方 – mgh = -ƒk d

機械能變化＝1/2質量末速度之平方－質量重力加速度高度

Nonconservative Forces, Example 2 (Spring-Mass)

非守恆力例2(彈簧－質量)����

Without friction, the energy continues to be transformed between kinetic and elastic potential energies and the total energy remains the same

無摩擦力時，能量在動能與彈力位能間不斷轉換而總能量維持不變����

If friction is present, the energy decreases

����有摩擦力時能量會衰減

ΔEmech= -ƒkd

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• 1 0 年前

解題策略， 3

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分析：確定配置的零勢能

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既包括重力和彈性的潛在能量

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如果有一個以上的武力行動在聯合國系統內，寫一篇表達的潛在能源與各部隊

解題策略， 4

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如果摩擦或空氣阻力目前，機械能的系統是不守恆

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使用能源與非保守勢力，而非

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之間的差別最初和最後的能量相當於能源轉化為或從內部能源的非保守勢力

解題策略， 5

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如果機械能的制度是保守的，寫的總能量

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英=文+ Uifor初始配置

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效率=的KF + Uffor最後配置

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由於是機械能守恆，工程=效應和可以解決的未知量

機械能源和非保守勢力

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一般情況下，如果摩擦是在代理制度：

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ΔEmech = ΔK + ΔU = - ƒkd

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ΔU是改變一切形式的勢能

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如果摩擦是零，這個等式變成一樣的機械能守恆

非保守力量，示例1 （幻燈片）

ΔEmech = ΔK + ΔU

ΔEmech = （的KF -文） +

（聯陣-義）

ΔEmech = （聯陣的KF + ） -

（文+義）

ΔEmech = 1 / 2 mvf平方-m gh= - ƒ kd

非保守力量，示例2 （春大眾）

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如果沒有摩擦，能源仍然是轉變之間的彈性動力學和潛在的能量和總能量不變

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如果目前的摩擦，降低能源

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ΔEmech = - ƒkd

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