Week 4 - What affects how long it takes a swing to go back and forth?

Lab:

    At the beginning of lab this week we began where we left off in lecture last week talking about friction. We used an example of a baby going down a slide with 3 different points on the slide. With those points we had to draw the forces that were acting upon them and the two that were actively moving had friction, gravity, and normal force acting on all of them. We talked about how the friction force is drawn in the opposite direction of the object, gravity is always straight down, and the normal force is always perpendicular to the surface. We then moved to talking about our next investigation of what affects how long it takes for a swing to go back and forth.  My group decided to investigate the variable of how far the swing is being pulled back. We used a string with weights attached at the bottom to simulate our swing and rider. Our string was attached to a rod to simulate a swing on a playground. We used a protractor to measure different angels we held the rope at, timing how long it took for the swing to go forward and backward one time. We found the average for 5 different starting points and concluded that the position the rider started at didn't impact the speed at which the swing moves back and forth.

Lecture:

    In lecture we talked continued to talk about the variables that we tested in lab as well as using a rope example to draw the forces acting upon it. We came to the conclusion that period does not depend on the riders weight but rather depends on the chain/rope length as the longer swing results in a longer period. Then we switched to talking about energy and how the term is used for a lot of things. I learned that energy is never created or destroyed but rather it's being transferred from one system to another. 

Textbook Reading:

What I learned: I learned that weight as well as angle of release have no affect on period length. The only thing that impacts period length is the length of the chain/rope/swing. I found these conclusions from our experiments to be quite interesting as we all came up with the variables we would be testing and had an idea that at least one of these would have an impact. I didn't think it would only be one! 

What was most useful: I really liked the image describing the difference between potential and kinetic energy as I always get them mixed up in my thinking. It helps me visualize the switch from potential to kinetic energy on the fall down, and then the switch back to potential energy as the pendulum swings upward.