Changes

<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 x d

''W'' = F · d

Or:

Or:

''W'' = F d sin θ

''W'' = F d sin θ

Where θ is the angle that separates the vectors. The second form of the equation is the expanded form of the "cross product" in the first equation. In physics, the cross product "a x b" (read "a cross b") can be rewritten as "a b sin θ".  

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 "a · b" (read "a dot b") can be rewritten as "a b sin θ".  

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.

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.