Originally posted by cikljamas
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Let's look at a situation inspired by Galileo's example. An observer on a train moving smoothly with velocity v either drops a ball or throws it horizontally with speed -v, ie with speed v in the opposite direction. We can compare this with an observer on the platform who either drops a ball, or who throws it (forwards) with v. We show the two points of view. Galileo chose lead or rock as the material so that the weight of the projectile would be much greater than the forces exerted on it by air. In our animation, air resistance is neglected.
Press "Play" in the link provided:
Galilean relativity and Newtonian mechanics (from Einstein Light)
![](http://www.animations.physics.unsw.edu.au/images/downloads_newton_train.gif)
Originally posted by cikljamas
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The angular speed of Earth's rotation in inertial space is (7.2921150 ± 0.0000001) ×10−5 radians per SI second (mean solar second).[27] Multiplying by (180°/π radians)×(86,400 seconds/mean solar day) yields 360.9856°/mean solar day, indicating that Earth rotates more than 360° relative to the fixed stars in one solar day.
Earth's_rotation
Earth's Velocities
Astronomers believe the "Earth" is moving at approximately 630 km per second with respect to this local co-moving frame of reference.
Milky Way - Wikipedia, the free encyclopedia
The Earth is traveling at an average speed of 828,000 km/h (230 km/s) or 514,000 mph (143 mi/s) relative to the galactic center
Galactic year - Wikipedia, the free encyclopedia
@cikljamas,
What are sun’s velocities above the flat earth?
Al
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