2. Work is only done by a force on an
object if the force causes the object
to move in the direction of the force.
Objects that are at rest may
have many forces acting on them,
but no work is done
if there is no movement.

3. W = F·d Work, Work is a scalar quantity.
by definition, is
the product of the force exerted on
an object and the distance the object
moves in the direction of the force.
W = F·d
Work is a scalar quantity.

4. The SI unit of work is the Joule, named in honor of
James Prescott Joule.
One Joule, J, of work
is the work done when
1.0 N of force is applied
through a distance of 1.0 m.

5. “Force vs. Displacement” graph.
Graphically, work is
the area under a
“Force vs. Displacement” graph.
displacement, m

6. the time rate of doing work; or the time rate transfer of energy.
Power,
by definition, is
the time rate of doing work;
or the time rate transfer of energy.
P = W / t
Power is a scalar quantity.

7. 1.0 J of energy is transferred
The SI unit of power
is the Watt,
named in honor of
James Watt.
One Watt, W, of power
is the power achieved
when 1.0 J of work is done or
1.0 J of energy is transferred
in a time of 1.0 s.