## Wednesday, December 13, 2017

### The physics of the spinning Earth

In 2014, Vsauce created a video that can almost entirely be explained by what we have learned about torque, inertia, and angular momentum.  For example, at the beginning of the video that every object at the equator of the earth is spinning at 465 m/s due East while he in San Francisco is spinning 368 m/s due East.  This can be explained by our equation for angular velocity and the fact that the earth is a sphere.  The radius of a sphere maximizes at a line that perfectly circulates its center, which on Earth is designated by the equator.  San Francisco is not at the equator, thus the radius of the circle that it is spinning around is smaller than the radius of the equator.  So, while both an object on the equator and San Francisco may have the same angular velocity, the larger radius of an object on the equator creates a larger linear velocity for it in comparison to San Francisco according to v = w*r.  Here is the link to the video: Vsauce Video, I highly advise everyone sees it, as Vsauce makes some interesting and well-made material.