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Q: physics of movement ( Answered ,   1 Comment )
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 Subject: physics of movement Category: Science > Physics Asked by: dudester123-ga List Price: \$15.00 Posted: 17 Aug 2006 13:25 PDT Expires: 16 Sep 2006 13:25 PDT Question ID: 757079
 ```The earth spins on it's axis at approximately 2 mi/sec(795 mi/hr), it spins around the sun at approximately 18.5 mi/sec(67,000 mi/hr), and the sun along with all of the planets spins around the center of the galaxy at 144 mi/sec(1/10th the speed of light. So how come we don't feel all of that motion?```
 ```Earth moves very fast. It spins (rotates) at a speed of about 1,000 miles per hour and orbits around the sun at a speed of about 67,000 miles per hour. We do not feel any of this motion because these speeds are constant. The spinning and orbital speeds of Earth stay the same so we do not feel any acceleration or deceleration. You can only feel motion if your speed changes. For example, if you are in a car which is moving at a constant speed on a smooth surface, you will not feel much motion. However, when the car accelerates or when the brakes are applied, you do feel motion. http://coolcosmos.ipac.caltech.edu/cosmic_kids/AskKids/earthmove.shtml This website also gives you a much deeper answer http://www.madsci.org/posts/archives/mar97/858262671.Es.r.html " Why don't we feel earth's rotation? In actuality, you do "feel" the Earth's rotation. You may not notice it, but it does affect us in minor ways. The Earth is rotating from east to west. This is why the sun rises in the east and sets in the west. This rotation causes toilets to flush clockwise in the northern hemisphere and counter-clockwise in the southern hemisphere. This effect can also be observed in a similar fashion in people. [Moderator Note: the effect from the rotation of the Earth diminishes quite rapidly at smaller scales; in the end, the resultant Coriolis effect on toilets, sinks, etc. is much too small to have a significant contribution to the direction of water flow. Please see Prof. Suzanne Willis' great answer for more. -- RJS]. If you walk from the north pole to the equator following a compass bearing of due south, you will gradually begin to stray to the left (or east). This is because as you move south, the Earth is moving west under your feet to the west, so each step you take lands you slightly further east than the last. It is also due to the fact that successively lower (closer to the equator) lines of latitude span a larger circular distance. Since the entire Earth must rotate at a constant rotational velocity, a spot on the Earth at 10 degrees latitude will have a higher absolute motion than a spot at 70 degree latitude. So as you walk south your surroundings begin to move faster and faster as you get left a little more behind with each step. By the way, you move right (also to the east) in the southern hemisphere as you walk north towards the equator for the same reason. This all has to do with inertia and perspective. You have intertia of rest and intertia of motion. We were born into a moving world so we started off with intertia of motion. Since we are not accelerating or decelerating (at least not fast enough for us to notice; the Earth's rate of rotation has varied over time) we continue living in our constantly spinning world. In the absense of this planet and atmosphere and any other gravitational effects, we would remain completely still in absolute space. What we notice on time scales we can understand from day to day comes solely from our perspective of our immediate surroundings. Since the Earth and atmosphere around us do not seem to move in relation to our position, we have no sense of motion. Even though the planet rotates about itself and about the sun, and our solar system rotates within the galaxy, we only notice movement of ourselves relative to our immediate surroundings. Take, for example, flying in a plane. Once the plane has reached its cruising speed, you no longer "feel" like you are traveling at over 500 mph. This is because the plane and the air mass within the plane is not accelerating or decelerating. You do have a strong gravitational pull from the Earth that makes it harder to walk forward than backward in a plane. This doesn't apply, however, when physically standing on the Earth. So, at any given moment, you may be rotating thousands of km/hour due to the Earth's rotation, rotating around the Sun at an even faster rate, being swept through the galaxy in our limb of the Milky Way, and being thrust through the universe as the galaxy moves. But we feel quite stationary on our planet. Movement is all based on perspective and since our perspective does not extend beyond our fixed surroundings, we feel next to no movement or rotation. Just don't plan a hike from the Northern Rockies to Baja California and expect to get there by following your compass south. Even though we may not feel like our rotating Earth has any effect on us, on very small distance scales and very long time scales, it does." --Keystroke-ga```
 dudester123-ga rated this answer: `thanks for the answer............`
 ```Is this why I keep falling off the treadmill and into the Starbux that's just a little south of the gym?```