Prompt Cast
The Physics Behind How Yo-Yos Work
TLDR Yo-yos have been around for centuries and have a design that allows them to spin on an axle, go up and down, and resist changes to their axis of rotation. They have been used to teach concepts like angular momentum and gyroscopic stability, and have even been connected to historical events.
Timestamped Summary
00:00
In this episode, the hosts discuss the physics behind how yo-yos work.
03:54
Yo-yos have been around since at least the 15th century and originated in the Philippines in the 1920s, with the modern incarnation coming after World War II in the Italian quarters of Philadelphia.
08:03
The modern yo-yo design originated in the Philippines and is characterized by a loosely looped string around the axle, allowing the yo-yo to spin once it reaches the end of the string.
11:55
The modern yo-yo design has both linear momentum and angular momentum, allowing it to go up and down and spin on an axle.
16:11
Yo-yos have gyroscopic stability, meaning that a spinning yo-yo will resist changes to its axis of rotation, similar to other spinning objects like footballs and Frisbees.
20:19
Increasing the mass and distributing it further away from the axis of rotation increases the moment of inertia and allows the yo-yo to sleep longer, which was a breakthrough in yo-yo design.
24:19
The yo-yo with the brain, released by Yomega in the 90s, had a clutch mechanism that allowed it to spin faster on the axis and shoot back up after slowing down.
28:24
Yo-yos were used by physics teachers to explain properties like angular momentum and gyroscopic stability, and there have been interesting connections between yo-yos and historical events, such as Abby Hoffman using a yo-yo during a House Un-American Activities Committee session, and Nixon's failed attempt at using a yo-yo.
32:32
The hosts discuss their difficulty in finding information about yo-yos that doesn't involve Yo-Yo Ma or other unrelated topics, and mention a charity album to raise funds for the Japanese earthquake and nuclear disaster.
Categories:
Society & Culture
