If the Earth rotated once every 48 hours or once every 12 hours instead of once every 24 hours, what would the effect be on A) Gravity  B) The Sun's warming effect and C) Tides?
137099
The earth IS slowing down, due to the friction effect of the molten core, though the pace of slowing is not noticeable in a person's lifetime. Gravity is unchanged, but weather patterns will change dramatically for 2 reasons - 1) a longer heating/cooling cycle (this assumes slow down) and 2) the reduced Coriolis effect that has great influence on weather cycles.\nTides will be less frequent.\nAlso changes in the earth's magnetic field (will reduce). When the field reduces sufficiently(or dissapears), we will lose our protection from cosmic rays, and life as we know it will end.\nFor more info I'd google this.\n\nen.wikipedia.org/wiki/Coriolis_effect - but wikepedia has other entires also
29960
Not true unless an abnormal event causes it to be so.  What will happen is that over time the Earth's rotation will slow down till the year and the day are the same amount of time.  Just like the Moon is right now.
313946
First the ocean tides would lessen by about 66% since the Moon effects the gravity of earth.  The sun causes the other portion of tides, so tiedds would continue, just a lesser amount.  After about 1,000 years the season would change because the moon keeps the earth's rotation axis and the plane of the orbit of earth within a narrow range.  That range would widen and there would be a more significant difference in the climate between summer and winter.  Many animals use the sequence of the moon for their life cycles (laying of eggs of the turtle, for instance).  So, these animals' life cycles would change, possibly causing extinction.  Additionally the moon provides nighttime light which many animals depend on for hunting as well as farmers depend on for harvesting.
158901
i dont' know what causes the rotation of an orbiting planet, but the moon would definitely have gravity even if it didn't spin.  that dude was full of crap.  if anything, the spin would cause things to fly off.
264954
Coriolis effect, the apparent acceleration of a moving body on or near the Earth as a result of the Earth's rotation. An object at the Earth's surface moves faster at the equator--because it is moving through a 25,000-mile (40,000-kilometer) circle in 24 hours--than it does away from the equator, where it travels in a smaller circle in the same 24-hour period. The Coriolis Effect alters the paths of projectiles on Earth. Everything from jets to ships to bowling balls are affected by it.
250524
Tidal forces are based on the gravitational attractive force. The relationship between the masses of the Earth, moon and sun and their distances to each other play critical roles in affecting tides.  \n \nGravity is one major force that creates tides. In 1687, Sir Isaac Newton explained that ocean tides result from the gravitational attraction of the sun and moon on the oceans of the earth (Sumich, J.L., 1996).\n\nNewton’s law of universal gravitation states that the gravitational attraction between two bodies is directly proportional to their masses, and inversely proportional to the square of the distance between the bodies (Sumich, J.L., 1996; Thurman, H.V., 1994). Therefore, the greater the mass of the objects and the closer they are to each other, the greater the gravitational attraction between them (Ross, D.A. 1995).\n\nThe moon is a major influence on the Earth’s tides, but the sun also generates considerable tidal forces. Solar tides are about half as large as lunar tides and are expressed as a variation of lunar tidal patterns, not as a separate set of tides. When the sun, moon, and Earth are in alignment (at the time of the new or full moon), the solar tide has an additive effect on the lunar tide, creating extra-high high tides, and very low, low tides—both commonly called spring tides. One week later, when the sun and moon are at right angles to each other, the solar tide partially cancels out the lunar tide and produces moderate tides known as neap tides. During each lunar month, two sets of spring tides and two sets of neap tides occur (Sumich, J.L., 1996).\n\nJust as the angles of the sun, moon and Earth affect tidal heights over the course of a lunar month, so do their distances to one another. Because the moon follows an elliptical path around the Earth, the distance between them varies by about 31,000 miles over the course of a month. Once a month, when the moon is closest to the Earth (at perigee), tide-generating forces are higher than usual, producing above-average ranges in the tides. About two weeks later, when the moon is farthest from the Earth (at apogee), the lunar tide-raising force is smaller, and the tidal ranges are less than average. A similar situation occurs between the Earth and the sun. When the Earth is closest to the sun (perihelion), which occurs about January 2 of each calendar year, the tidal ranges are enhanced. When the Earth is furthest from the sun (aphelion), around July 2, the tidal ranges are reduced (Sumich, J.L., 1996; Thurman, H.V., 1994).
158267
If that direction were opposite the direction of the \nearth's rotation, I think the answer is theoretically yes.\nIn reality there's not enough mass of people relative to the mass of the earth to have any effect.
62084
300 million years ago the day was about 22 hrs long. Earths rotation is getting slower and the days will be getting longer. This is because of the tidal forces between the earth and the moon. Earths oceans are being pulled on by the moons gravity. But as the moon moves in its orbit the oceans cant follow in a nice bulge because of the continents. So the oceans form another gravitaional centre offset from the center of the earth. This out-of sync tug is whats making the moon move farther away from the earth. The same force is slowing the earhts rotation. The moon is moving away from the earth by a couple of cms/year. How much longer the day gets each year I cant remember. It´s in the neighbourhood of nanoseconds. A leap second was acutally added to 2005.
212868
Not much.  The moon was not significantly that much closer to the Earth only 400 million years ago.  As such, while the tides would have been slightly higher and lower, there would not have been enough of a difference to make anything different for life.\n\nIn short four hundred million years ago the gravitational effects of the moon played the exact same roll they do today.
615490
I don't think anyone has done the math to figure out how quickly it would happen but with out the moon the Earth's rotation on it's axis would not be stable where it is now.  If that got out of wack we would have some serious weather problems.  It's the tilt of the Earth not the distance from the sun that makes the difference between summer and winter.  So if that wobble that has the the northern hemisphere facing the sun in the summer and leaning away at 23 some degrees in the winter was screwed up we'd probably all die.  There's a good move called, odly enough< If we Had no Moon.  It's from the discovery channel, and you can buy it or just check their TV schedule, it comes on once or twice a year.
438864
Nothin would happen.\nIf you consider two bodies the earth (name it E) and a large mass (m). \ninitially M rests on E. and you lift mass M. the force used to lift it will also act on E.\nAlso if you consider the mass M and E. as a system force exerted on dropping M would be internal and since internal forces do not cause acc. the Earth will not get unbalanced.\n\nThats good for us isn't it...
514297
Gravity is proportional to the mass of the planet.  I'd say the acceleration on this planet is 0.1045 * 9.81 m/s^2.  \n\nFor b) use x =  1/2at^2\n\nt = time  \na = acceleration due to local gravity
620442
Earth is revolving in orbit, held in place by the Sun's gravitational pull
507357
On average the sun moves about 1 degree against the background stars per day (that's about 2 full moons!).  Since the Earth is on an elliptical orbit, we actually speed up and slow down, so it changes from day to day the exact amount.  \n\nIf you mean how many degrees above or along your local horizon, you need to give me your latitude and longitude to answer that.
464252
I'll assume it is your typical physics problem, which states some highly simplified conditions to demonstrate some physics principal and not a real engineering or natural science problem. We will assume the Earth increases its radius by 30 meters without any change in total mass, and that the Earth is a sphere of uniform density. In that case, the rotation rate would be proportional to the change in the moment of inertia of the Earth, I. For a uniform sphere I=2/5MR^2. You need to calculate the existing I and the new I after the radius change. Since M does not change, and we want only the ratio of the two Is, we can ignore the 2/5M and just compare radius. The radius of the Earth is about 6,370km or 6,370,000 meters. Adding  30 meters makes it 6,370,030 meters and the ratio of 6,730,030^2/6,730,000^2 is about 1.00001. That is about a 0.001% change, and about 0.001% of 24 hours is about 0.8 seconds. \n\nAs an angular momentum problem it is neat, but as a real life Earth problem it is totally bogus. There are all sorts of complications, like the sea only covers 70% of the Earth, the density of water is less than the average density of the Earth, the ice that melted started out far above sea level in many cases, and so on.
371118
because the earth rotates on an axis
146261
The sun rotates approximately once for every 27 Earth rotations.  Unlike the Earth, because the sun is gas, it does not rotate at the same rate at all locations.  If the Sun were to stop rotating, it would probably collapse inward possibly resulting in an enormous explosion as the particles within the core became superheated.