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Pendulum Science Shop Games

A rudimentary pendulum has a weight, referred to as a bob, connected to the end of a string or rod that hangs from a pivot point. A pendulum uses gravity for motion, once it has been acted upon by an outside force. Pendulums use potential energy (stored energy) when the bob has swung up to it highest position, and kinetic energy, or movement, as it travels down from it highest point to the other end of the arc. Pendulum motion and behavior can be demonstrated in a simple science shop game, involving participants and a few basic tools and props.

Location &Materials
- Assemble a group of students in a playground area equipped with a swing set. The students should have personal notebooks and writing utensils with which to take notes of every phase of the science game project. A teacher or instructor should clearly be in charge and ready to lead the students by direction and assignment.
Preparation
- Pick out a functioning swing, one that clearly works and is safe for use. Equip one student with hand-held stopwatch. Pick a student to serve as the swing rider, preferably a smaller than average size student for the first phase of the game project. Have the small student sit in the swing, body immobile with legs still and tucked in one position.
Science Game Phase 1
- Have a student gently push the swing rider and back off. Have the students who has the stopwatch count the number of individual swings from one arc to the next, for a duration of 1 minute. After the minute has elapsed, have the students record the total number of swings in their notebooks. Replace the smaller student with a larger, heavier student and have the gentle push repeated. Have the stopwatch student record the number of swings in 1 minute for the heavier student. The other students should record the results.
Science Game Phase 2
- Have the smaller student pushed very hard from a standing stop, so the swing arc is much higher. The stopwatch student will record the number of swings in 1 minute and call out the number for the students to record in their notebooks. Exchange the lighter student with the heavier student, and repeat the same hard push. The stopwatch student will record the swings and call out the number.
Science Game Phase 3
- Have the smaller student receive a gentle push, then begin to pump his or her legs, aiding in the momentum of the swings for 1 minute. The stopwatch student will record the number of swings and call out the number to the others.
Science Game Phase 4
- Have the heavier student receive a gentle push, then begin to pump his or her legs, aiding in the momentum of the swings for 1 minute. The stopwatch student will record the number of swings and call out the number to the others.
Results and Determinations
- After the four phases, the teacher will ask the students questions about what they observed and recorded, such as: How did the weight or mass of the different students in the swing effect the numbers of swings? Did the heavier student produce more swings per minute, and if not, why? What was the difference in the number of swings of the smaller student when the gentle push and hard push was applied? Did the harder pushing force create more swings per minute? How does mass affect the swing of a pendulum?
More Questions
- Explain that pumping the swing used kinetic (moving) energy, rather than dissipating energy, and ask why students think it affected the number of swings per minute. Ask why it is called potential (stored) energy when the swing is momentarily motionless at the top of its arc. Ask how gravity is affected by weight and increased kinetic energy.

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