Difference between revisions of "Forest UCM Energy KEnWork"

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: <math>\frac{dT}{dt} = \frac{m}{2} \frac{d}{dt}v^2= \frac{m}{2} \frac{d}{dt}\vec v \cdot \vec v</math>
 
: <math>\frac{dT}{dt} = \frac{m}{2} \frac{d}{dt}v^2= \frac{m}{2} \frac{d}{dt}\vec v \cdot \vec v</math>
 
::<math>= \frac{m}{2} \left (\vec \dot v \cdot \vec v + \vec v \cdot \vec \dot v \right )</math>
 
::<math>= \frac{m}{2} \left (\vec \dot v \cdot \vec v + \vec v \cdot \vec \dot v \right )</math>
 +
::<math>= \frac{m}{2} 2 \vec \dot v \cdot \vec v  = \vec F \cdot \vec v</math>
 +
 +
or
 +
 +
: <math>dT = \vec F \cdot \vec v dt</math>
 +
  
 
[[Forest_UCM_Energy#KE_.26_Work]]
 
[[Forest_UCM_Energy#KE_.26_Work]]

Revision as of 12:49, 15 September 2014

Definition of KE

For a single particle of mass m moving with a velocity v, the kinetic energy is defined as

[math]T \equiv \frac{1}{2} mv^2[/math]

Work Energy Theorem

Derivation

Consider the Kinetic Energy's temporal rate of change assuming that the mass of the particle is constant

[math]\frac{dT}{dt} = \frac{m}{2} \frac{d}{dt}v^2= \frac{m}{2} \frac{d}{dt}\vec v \cdot \vec v[/math]
[math]= \frac{m}{2} \left (\vec \dot v \cdot \vec v + \vec v \cdot \vec \dot v \right )[/math]
[math]= \frac{m}{2} 2 \vec \dot v \cdot \vec v = \vec F \cdot \vec v[/math]

or

[math]dT = \vec F \cdot \vec v dt[/math]


Forest_UCM_Energy#KE_.26_Work