Funnest Swing Design

This year, Mr. Williams combined units six, Energy and Momentum of Rotating Systems and seven, Oscillations. In this combination of units, I was in a group with Sophia Schiltgen, Clare Zhu, and Deepti Bhat and we were asked to design our own tree swing/cool amusement-parky-thing that has harmonic motion. The after we excecuted our design, we were asked to determine the number of connecting ropes, length of rope(s), period, maximum speed, arc length, angle, maximum height for your mass on the swing and the maximum and minimum tensions as we rode it. 

Process

From the beginning, my group knew that we wanted to be unique, not boring like some other swings. While others focused on making a simple wooden swing with just a plank of wood and rope, we decided to make a tire swing. We were mostly inspired by the tire swing in Pioneer Park but we quickly realized that, that tire was a monster truck tire, a tire we would have a real hard time getting our hands on. But we made a couple of stops at various stores and got a tire for free and some rope. 

Once we got everything we needed, we built our tire swing. Midway through building it, we realized we didn't have enough time or rope to have another "loop" around the tire, so we were stuck with three points of contact with the rope and the tire. But don't worry! Sophia is very balance-able and has not been harmed in any way, shape, or form. 

We took the vidoeo of Sophia on the swing and we went straight to calculating. We found everything we were supposed to like the period and the maximum speed it went but, when we were calculating the energy conservation for the part where we applied torque, we realized Sophia was spinning not due to harmonic motion but due to the twisting of the rope. We did some more research and discovered that in our senario, there was another energy present: Torsional Potential Energy. 

Content

Peirod (T): the time it takes for one complete cycle of a periodic motion/oscillation; T = 1/f

Amplitude (a): the maximum displacement of a point on the wave from its equilibrium position

Moment of Inertia (I): a measure of an object's resistance to rotational acceleration ¹

Angular Momentum (w): the "spin" of an object

Conservation of Angular Momentum (L): in an isolated system, the total angular momentum remains constant (L = L)

Torque (τ): a twisting force that tends to cause rotation; τ = r⊥F = rF⊥

Angular Acceleration (α): rate at which an object's angular velocity changes over time; α = r/a = τnet/Isys

Torsional Potential Energy (Ut): the energy stored when an object rotates around another (being twisted); Ut = ½Kθ²

Torsional Constant (K): property that describes a material's resistance to twisting or torsion; K = τ/θtwist

Rotational Kinetic Energy (Krot): energy an object has due to its rotation; Krot = ½ (I) ω²

¹ each object's moment of inertia is different according to the fraction in front of the standard equation: I = MR² (R could also be the length (L) instead of the radius)

Reflection

I really enjoyed and loved this project, and I learned a lot from it, but as a reflection of my work focusing on the 6C's, I think I did well being a good communicator and collaborator. As a communicator, my group expressed our individual thoughts and ideas about the project, and we worked together to incorporate them. I think we all were good collaborators because throughout the project, we maintained positive attitudes, and we had a good time setting up the swing, going on it, pushing each other, etc. 

But I think I could work on two things: being a conscientious learner and being more culturally competent. At times, my group and I would have too much fun with our tree swing, and we would occasionally forget about the reason we are outside. We were also almost too focused on the tree swing at Pioneer Park that we didn't explore any other possibilities/ideas of tree swings on a bigger scale.