1. Force- a push or a pull on an object.

2. Load Force- the weight of the object being moved.

3. Load Distance- the segment of string or cord between the pulley and the load.

4. Effort Force- the amount of force required to move a load.

5. Work- a force applied over a distance. Work is calculated by multiplying force times distance.

6. Joule (J)- the unit used to measure energy and work.

7. Mechanical Advantage- a value which describes the relationship between a load force and the effort force needed to move the load. Mechanical advantage can be calculated either as the ratio of load force to effort force or the ratio of effort arm length to load arm length.

8. Effort Arm- the section of lever between the fulcrum and the effort in a lever system.

9. Effort Distance- the segment of string or cord between the effort and the pulley in a pulley system.

10. Load Arm- the section of lever between the fulcrum (the pivot) and the load in a lever system.