Key Equations

$W = F_{x} \Delta x = Fd \ \cos \circleddash$

Work is equal to the displacement an object moves multiplied by the component of the force in the direction the object is moving

$W =$ work

In Joules; work is just energy being transferred

Vocabulary

Work: the transfer of energy

Displacement: A vector that describes the difference between final and initial position

Force: A push or a pull on an object

Work

When a force acts upon an object to cause a displacement of the object, it is said that work was done upon the object. There are three key ingredients to work - force, displacement, and cause. In order for a force to qualify as having done work on an object, there must be a displacement and the force must cause the displacement. There are several good examples of work that can be observed in everyday life - a horse pulling a plow through the field, a father pushing a grocery cart down the aisle of a grocery store, a freshman lifting a backpack full of books upon her shoulder, a weightlifter lifting a barbell above his head, an Olympian launching the shot-put, etc. In each case described here there is a force exerted upon an object to cause that object to be displaced.

The concepts of work and energy are closely tied to the concept of force because an applied force can do work on an object and cause a change in energy. Energy is defined as the ability to do work.

Seems like a bit of circular logic, but think of it this way.  You can apply a force on an object to change the property of that object.  Simply put imagine pushing a stationary bowling ball, now a couple of things might happen. If the ball is on a smooth flat track the ball will start rolling then start going faster and faster.  Next if the bowling is pushed up a steep incline, so steep that the ball never really picks up speed, as a matter of fact, when you reach the top of the hill and you stop pushing, the ball stops.  Lastly If the ball is on a rough track, so rough the ball wont move.

1.  In the first case the work done on the ball speeds it up, increasing it motivational energy (call kinetic energy)

2.  Work is still done in the second case even if the balls speed doesn't change.  At the top of the hill the ball has the potential to go faster, potential energy.  If the ball slides down the hill, it will go faster and faster.

3.  In the third case, the energy of the bowling ball doesn't change, it's motion doesn't change nor does its height.

Example

How much work is done by a person who uses a force of 30.0N to move a grocery buggy 15.0m?

Work = Force * Displacement

Work = (30.0 N) * (15.0 m)

Work = 450.0 J  (a Newton (N) x a Meter (m) is a Joule (J))