Work & Energy
When work is done, the energy of an object changes.
Work is the transfer of Energy. π = π₯πΈ
Energy is the ability to do work.
Work is done when an applied force moves an object.
π = πΉ!"" π₯π
πΉ!"" πππ π₯π ππ’π π‘ ππ ππππππππ π‘π πππβ ππ‘βππ
Units: 1J = 1Nm
Work is a scalar quantity.
What if πΉ!"" πππ π₯πare not parallel?
F
d
Only the component of the applied force in the same direction as the displacement does work:
π = πΉ!!"#$!%&'( π₯π
π = πΉ!""#$%& πππ π π₯π
πis the angle between F and π₯π
π = πΉ!""#$%& π₯ππππ π
If π=0 then cosπ=1 and π = πΉ!"" π₯π
If π= 90 then cosπ= 0 and π = 0
(e.g. satellites)
π = πΉ!""#$%& π₯π πππ π
or π = πΉ!"" π₯π
0
