POINTING FUSE: CONSERVATION IN ACTION

Grades 9 and up./ Physics class.

One or two class periods or one hour of independent study.

Students will apply physics definitions and relationships to solve problems and answer questions about the mechanism for turning a satellite in orbit.

Vectors, Newton's Laws of Motion, Conservation of Linear Momentum, Force, Gravity, Torque, Center of Mass.

Student activity sheet and scientific calculator.

1. Ask students how objects are made to turn. 

2. After students have read “Turning in Space” on the activity sheet, ask students to speculate on how making an object turn is different in space. If it is available, show a few minutes of the astronauts in space video. 

3. (Optional) Have students model torque by pushing with equal but opposite forces on the two ends of a pencil placed on a desktop. Model the action of gas jets with balloons. Model the reaction wheel by having a student on a rotating platform hold a spinning weighted bicycle wheel. You can also ask a student to try to turn while sitting on an office chair that swivels with her feet off the floor. 

4. Ask students to complete the activity sheet by working in groups in class or individually as a homework assignment or assessment.

This activity can be used as an application of the concept of conservation of angular momentum after it has been taught or it could be used to introduce the concept. In either case, the exercises draw on students’ previous knowledge and the activity could be used as an evaluation instrument. The exercise could be done as a group project or could be assigned for independent study.