Changes

In [[physics]], work refers to the product of [[force]] and [[distance]] vectors

In [[physics]], '''work''' refers to the [[dot product]] of [[force]] and [[distance]] vectors

<ref>Serway and Beichner, ''Physics for Scientists and Engineers'', Fifth Edition</ref>.

.<ref>Serway and Beichner, ''Physics for Scientists and Engineers'', Fifth Edition</ref>

''W'' = F · d

<math>W = \vec{F} \cdot \vec{d}</math>

Or:

Or:

''W'' = F d Cosθ

<math>W = Fd \cos{\theta}</math>

Where θ is the angle that separates the vectors.

Where θ is the angle that separates the vectors. The second form of the equation is the expanded form of the "dot product" in the first equation. In physics, the dot product <math>\vec{a} \cdot \vec{b}</math> (read "a dot b") can be rewritten as <math>|\vec{a}| |\vec{b}| \cos{\theta}</math>.  

Work is a transfer of [[energy]]; if ''W'' is positive, there is a transfer of energy ''to'' the system, and if ''W'' is negative there is a transfer of energy ''from'' the system.

When the force is not constant, the correct expression uses [[integration]]:

Its units are that of force multiplied by distance, in SI this is [[newton (unit)|Newton]] · [[Meter]], or [[Joule]]

 

 

Its units are that of force multiplied by distance, in SI this is [[newton (unit)|Newton]] · [[Meter]], or [[Joule]]. The aberrant unit kWh (kilowatt-hour) is sometimes used; this unit is the product of kilowatt, or 1,000 Watts (Joules per second), and hour, or 3,600 seconds.

==References==

==References==

<references/>

<references/>

[[category:physics]]

[[Category:Physics]]

[[Category:Mechanics]]