Skating and angular momentum!

Purpose/ProblemConservation of angular momentum is the principle that the angular momentum of an object remains constant as long as no external torque, or moment, acts on that object. When a figure skater is in the air, he or she is rotating about his or her center of mass and possess a certain amount of angular momentum. The only external force is gravity. However, gravity acts vertically down through the center of mass (COM) of the skater. Since gravity acts through the axis of rotation of the skater, it does not cause a torque and can not change the skater's angular momentum.In this project I’ll explore methods of finding how momentum changes in response to different variables.

HypothesisI believe that the more weight that I put on my

self the faster and longer the chair will spin, because it’ll carry it’s momentum much longer

than something lighter. Something lighter would most likely lose its momentum in a short period

of time.

Materials

• The materials I’m going to use are:• Chair• Weights

Variables

• Dependent Variable: How fast I go, how many revolutions I make.

• Independent Variable: The minute reactions the person spinning the chair makes.

• Controlled Variable: The environment I’m in, the materials I use.

Procedure

• I’ll conduct this experiment by spinning the chair for five seconds, and I’ll record how many revolutions I make in the following circumstances:

• Hands in lap• Arms out• Weight’s and arms out.

Qualitive Data

• The more I spun the chair the dizzier I got. • The chair moved a similar amount of

revolutions no matter what different variables I used.

Quantitative data

• Spins: Weights Folded hands Open arms• 1st try 3 3 3• 2nd try 3 4 4• 3rd try 2 ½ 3 4

Graph

Distribution graph.

Results

• There was a slight variation in the results. Not much but when I had my hands in my lap the chair rotated noticeably faster. So,my conclusion is that my momentum would carry me at a similar speed regardless of my position.

Pictures

Pictures

Conclusion

• Momentum stayed constant pretty much throughout, proving that a dramatic change in weight would be necessary to change the nature of the spin, or the amount of times it’d spin.