Objective:  Students will define, explore and give examples of a force (push or pull) OR doing "work"  (scientific term).

Materials:  push pins, sponge, rock, eraser, cork, chair, rope, teacher's desk, a cabinet that will not move, Science Journal

Vocabulary:  force, work (scientific term)

Duration: 1 or 2 days, 30-40 minutes

Grouping:  Whole class or coop groups

Preparation:  Set up for the experiment.

Activate prior knowledge:  Ask students to describe some of the things they did before school where force (push or pull) was needed.  Write ideas on the board. Ask: "Did you  do work?"

Activity:  (1) Discuss the scientific meaning for the word work and how this meaning is different from the everyday use of the word work.
(2) Line up the items (sponge, rock, eraser, cork).
(3) Ask the students what they think will happen when they try to push the pin into each item.(hypothesis) Take a push pin and push (force) it into the sponge, rock, eraser, and cork.  What happened?(result)--Discussion
(4) Tie a rope around a chair. Pull.  What happened?(result)  Tie a rope around the teacher's desk.  Pull.  What happened?(result)  Tie a rope around a cabinet. Pull.  What happened? (result)
(5)Conclusion:  The students should come to the conclusion that work was being performed when the push pin was forced into the sponge, eraser, and cork because the push pin moved.  Work was also being performed when the chair and desk moved.  No work was being performed when the push pin was forced on the rock or when the cabinet did not move.
(6) Guide the students when writing this experiment in their Science Journals.  Don't forget to follow the scientific procedure.

Follow-up or Homework:  Cut out two pictures of people doing work and one picture of a person doing no work.  Write one or two sentences for each picture (explanation).  Bulletin board?