Will the Washers Swing? | Coffee Cup Pendulum

Will the Washers Swing? | Coffee Cup Pendulum Coffee Cup Pendulum Experiment (Coffee Cup on a string) Made for parents and teachers Made for parents and teachers, this video presents an engaging **science experiment**: the coffee cup pendulum! It's a fantastic **do it yourself** project for **science for kids**, perfectly demonstrating the principles of **periodic motion** and even **simple harmonic motion**. Learn how to set up your own pendulum at home and make predictions about its movement! Chapters 0:00 Intro 0:05 What you need 0:30 Washer Experiment 1:00 Science behind it 1:33 Coffee cup experiment 2:14 Slow motion 2:39 Set up Kids Fun Science Online Store https://teespring.com/stores/kids-fun-science How it works: You need a washers, a pencil, a coffee cup or washers, and about 25" to 30" of string. Tie one end of the string to the cup and the other to the washers. Hold the pencil in one hand and drape the string over it so the cup hangs down a short distance. Hold the washers with your other hand (arm stretched out to the side), slightly below the level of the pencil. When you let go of the washers, will the cup fall and crash into the floor? When you let go of the washers, it falls down in an arc about the washers. At the same time, the cup accelerates downward, reducing the radius of the washers arc dramatically. As the washers spirals inward around the pencil, its velocity increases rapidly (conservation of angular momentum) and it very quickly winds around the pencil several times. It takes only three or four windings around the pencil to stop the cup from falling any further. The friction between the string and pencil increases exponentially with the number of windings. Vary the length of the string. Try coffee cup, metal washers to tie to the ends of your string. Can you figure out the best ratio of washers? Let us know in the comments below what your ratio was and worked or didn't work. What works better? A finger? A pencil? Does this work every time? Why? #coffeecuppendulum #pendulum #pendulummagic