Difference between revisions of "Kinetic Energy"

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(Some fairly big changes. Could use some help with the format of definite integrals for the work-energy theorem in non-constant forces.)
m (Fixed a bunch of typos and format errors.)
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'''Kinetic energy''' represents the [[energy]] asociated with the [[motion]] of an object.<ref>Serway and Beichner, ''Physics for Scientists and Engineers'', Fifth Edition</ref> It is defined as:
 
'''Kinetic energy''' represents the [[energy]] asociated with the [[motion]] of an object.<ref>Serway and Beichner, ''Physics for Scientists and Engineers'', Fifth Edition</ref> It is defined as:
  
K ≡ [[mass|m]][[velocity|v]]<small>2</small> / 2
+
K ≡ [[mass|m]][[velocity|v]]<sup>2</sup> / 2
  
 
The change of kinetic energy in an object is equal to the total [[work]] done on it by a [[force]]. In the case of constant force, this can be expressed as:
 
The change of kinetic energy in an object is equal to the total [[work]] done on it by a [[force]]. In the case of constant force, this can be expressed as:
  
Σ''W'' = ΔK = mv<sub>f</sub><small>2</small> / 2 - mv<sub>i</sub><small>2</small> / 2
+
Σ''W'' = ΔK = mv<sub>f</sub><sup>2</sup> / 2 - mv<sub>i</sub><sup>2</sup> / 2
  
Where v<sub>f</sub> is speed at t = 0 and <sub>i</sub><small>2</small> is speed at time = t.
+
Where v<sub>i</sub> is [[speed]] at t = 0 and v<sub>f</sub> is speed at [[time]] = t.
  
 
Kinetic energy is a scalar and has the same units as work (i.e. [[Joule]]).  
 
Kinetic energy is a scalar and has the same units as work (i.e. [[Joule]]).  

Revision as of 16:19, October 17, 2007

Kinetic energy represents the energy asociated with the motion of an object.[1] It is defined as:

K ≡ mv2 / 2

The change of kinetic energy in an object is equal to the total work done on it by a force. In the case of constant force, this can be expressed as:

ΣW = ΔK = mvf2 / 2 - mvi2 / 2

Where vi is speed at t = 0 and vf is speed at time = t.

Kinetic energy is a scalar and has the same units as work (i.e. Joule).

References

  1. Serway and Beichner, Physics for Scientists and Engineers, Fifth Edition