The document discusses the definition of work in physics, explaining that work requires both a force and a movement or displacement of the object. It provides examples of lifting a box, pushing a box, and pushing on a wall to illustrate that work is only done when a force causes an object to move, not simply by applying a force alone. Work is quantified as the product of the force applied and the distance of movement or displacement.

2. Work
Lifting Force
Movement Distance
What force is
having to be
overcome by the
lifting force?
Weight

3. Work
must be in the
same direction
Pushing Force
Distance Moved
What force is
having to be
overcome by the
pushing force?

4. Lifting Force
Movement Distance
Is the man doing work
when he lifts the box?
Yes.
Is the man doing
work when he holds
the box?
No!
Is the man doing
work if he carries
the box?
yes!
(But he IS applying a force)

5. Think about pushing on wall that does not move.
A force is applied but the wall has not moved a
distance.
Is work
done?

6. Work
Think about pushing on wall that does not move.
A force is applied but the wall has not moved a
distance.
Is work
done?
No!
But I did expend
energy applying a
force!