## Work

**Mechanical work (W)**is done on an object when a force displaces the object in the direction of the force or a component of the force. Work is a scalar quantity. Mathematically we can derive the following equation when force and displacement are in the same direction, where the force (F) is multiplied by the displacement (∆d):

When the force and displacement are in different directions, a different equation is used:

## Sample Problems

## Graphing Work

Work can also be represented on a graph by plotting the magnitude of the force

(F), on the y-axis and the magnitude of the object's position (d) on the x-axis.

The F-d graph on the left shows the constant force acting through a displacement (the red part).

(F), on the y-axis and the magnitude of the object's position (d) on the x-axis.

The F-d graph on the left shows the constant force acting through a displacement (the red part).

**Positive**and**negative work**(when the force and displacement are in opposite directions) can also be displayed on F-d graphs. The second part of this graph, represents work done by a**changing force**, where the force uniformly decreases. The work can be calculated from an F-d graph by calculating the area underneath the graph.## Practice

**Worksheets/ Quizzes**

1. https://docs.google.com/viewer?a=v&pid=sites&srcid=ZGVmYXVsdGRvbWFpbnxtcnRyYXNrc3BoeXNpY3N8Z3g6MTUzOGI4OTJjMDFjNWMzZg (practice problems)

2.

__http://www.sparknotes.com/physics/workenergypower/workpower/problems.html__(practice problems)

3.

__http://www.physicsclassroom.com/calcpad/energy/problems.cfm__(practice problems)

4.

__http://glencoe.mcgraw-hill.com/sites/0078768349/student_view0/unit2/chapter5/math_practice_5.html__(multiple choice)

5. http://www.dctech.com/physics/help/problems.php?problem=energy-work&question=1&variant=1 (practice problems)

6. http://www.education.com/study-help/article/mechanical-energy_answer/ (practice problems)

7. http://www.physics247.com/physics-homework-help/work-power.php (practice problems)

8. http://www.softschools.com/quizzes/science/work/quiz1692.html (work-multiple choice quiz)