Work
Done = Force*Distance only applies when a constant force acts in the
direction of movement. To find the work done when a constant force
does not act in the direction in which a particle moves we use the
dot product:
A Level Maths Notes: M5 – Work Done by a Force in Moving From Point to Point
The equationWork
Done = Force*Distance only applies when a constant force acts in the
direction of movement. To find the work done when a constant force
does not act in the direction in which a particle moves we use the
dot product:
For, example when a particle
moves from
to
under
the action of the force
we
first find the displacement vector from the start point to the end
point:
The work done is then
The dot product
where
e_d is the unit vector in the direction of
returns
the component of
in
the direction of(
)
as shown below. Multiplying this by
gives the work done by the force.
