Does water slow down gravity?
605564
Water doesn't slow down gravity. Gravity always pulls things down at roughly 9.8 m/s^2 (at most places on Earth, anyway). What happened, though, is that the water slowed down the desent of the coins. Remember, water is a molecule. When gravity pulled the coins down through the water the water molecules pushed back up against the coins. Its Newton's law, "for every action there is an equal and opposite reaction." Air actually works the same way. Its called terminal velocity. If you jumped out of a plane you can only fall so fast before the force of the air molecules acting against gravity equals the downward force of gravity, thereby keeping you from accelerating downward to a faster speed.\n\nNow, as for why one hit sooner then the other, that's because of how they fell. If the coin fell flatwise on the water it falls slower because there is more surface area of the coin in the way of the water. If the coin falls on its edge there is less surface area of the coin to meet the opposing force of the water and, therefore, less resistance (although the coin will flop around and turn from the force more readily). Actually, predicting a coin's free movement through a liquid is quite difficult and involves a lot of fluid dynamics and center of mass stuff.\n\nFor short distances, though, you can generally fake a rough estimate by simplifying math. You know those things with a fishbowl and a shotglass that most places like Perkin's have? Where if you drop a quarter into the glass you get a free cookie or something? Most people drop the coin edgewise and then wonder why the coin misses. The best way to do it is drop the coin in flat over the glass because the force acting against the coin is more balanced and less prone to exerting a torque the the coin as it falls. Try it sometime and see for yourself.
152879
No, it will not.  The other answers to this question are on the right track, in that they point out that an object's density is the key thing in most situations, since if it is less dense than the fluid it is in, it will displace fluid equal to its weight before it is completely submerged, and hence float.\n\nBut in *this* problem, we are told from the outset that there is not enough water to be displaced.  Therefore, the object will displace all the water, all 1 lb. of it, and still not have displaced enough water to equal its weight.  Therefore, it will rest on the bottom, i.e. not float.
811736
If the water is full of air bubbles, its density is reduced. You loose buoyancy and sink.\n\nWhen there is a natural gas blow out under floating oil platforms, they have been known to go down almost instantly.
382643
Yep, Sue's right. Toward gravity is down, away from it is up.
810879
The problem is not the weight of the water, it's the drag of the fluid. Unless you can find some magic way to eliminate the drag in a fluid like water which is so much more than that of a gas, you will be stuck with lower speeds. Even if you had some "magic" bubble around the sub, you would still need to displace the liquid to move the bubble.
444674
if you drop something in the water, it displaces water, and that displaced water moves other water, the rock going down in teh water pushes some up, which then pushes some down, and so on and so on.
208900
Specific gravity.\n\nPure water has a density of 1 (the mass of 1 cubic centimetre of pure water is precisely 1 gramme), if something was twice as heavy as water (i.e. it has twice the mass) it would have a specific gravity of 2, 6 times as heavy and the SG would be 6.  If something was half as light as water it's SG would be 0.5 and so on.
533474
WEll where will water fall. i mean when ever i saw water its on sealevel then where the hell will water fall. yeah water falls but from clouds. There is a word gravity. which plays important role. else after birth u wud have not fallen down. u wud be somewhere in sky.
21135
water on the ground, in oceans, lakes, etc. has enough energy to evaporate a little bit (all liquids have a "vapor pressure," which is higher the hotter it is).  eventually, there is too much water in the air at whatever air temperature it is, so the water re-liquifies and falls.  this can commonly happen when a warm front (warm air holds lots of water) is cooled by a cold front.
156716
in reality, it is the surface tension (adherance of molecules to one another) and density of the fluid\nbecause the question does not state that the object is suspened in the fluid\n\notherwise the force acting to keep an object buoyant would need to equate and thus counteract the objects weight (which is the force of gravity pulling said object down)\n\nmass X volume = density which is a factor in determining a force acting upon the object; a force working to cause the object to disperse within the less dense fluid or conversely the fluid to compress and colapse the object\n\nSo the author of the question given is expecting the answer: weight
65207
mck\n14 hours ago\n\nReport Abuse\n\n\nIt is true that gravity increases the velocity of a falling object. However, there is also air resistance, which slows an object down while it is falling. This is dependent on a number of variables, one of which is the current velocity of the object. Therefore, as gravity causes the speed to increase, air resistance causes it to not increase as fast. At a certain point, the *terminal velocity* is reached, which means that the raindrop cannot speed up (because of air resistance) and cannot slow down (because of gravity).\n\nIf you actually mean why it doesn't hurt because of pressure, that's because a raindrop is "soft" - it can change shape when it hits your skin. However, freezing rain, although small, can hurt (I know from experience). Again, the velocity isn't great enough for it to actually puncture the skin (usually). \nSO the main causes r terminal velocity and air resistance.
17074
The moons gravity is what causes ocean waves. It affects big bodies of water such as oceans or seas but as for water in a toilet I highly doubt because if you think about it, the moon's gravity doesn't effect pond water. The only thing that would affect toilet water is water pressure, and on the global scale the Corriolis Effect. But that only effects the direction of the water when flushed. So the most probable cause is the water pressure of your city.
770625
I'm sorry, i have to correct some of the misunderstandings posted above here.\n\nTHE WEIGHT DOES NOT, I REPEAT, DOES NOT CHANGE IN WATER.   weight is a term in physics for the interaction of gravitational forces on a masseous object.  Does the mass of the object change in water?  NO.  Does the mass of the earth change when an object enters water?  NO.  Therefore the weight is the same.\n\nWhy do objects feel lighter in water?  the difference in net force is the answer.  Weight still pulls down equally... However, the water creates a boyent force which counteracts a percentage of the weight (depending on the object submerged.  roughly counteracts 40% for humans, different for other objects).  In this way, while the weight is the same, the downward force of the object is less.  That's the confusion point for almost everyone who's answered so far.
462904
Here's how it works:\n\nThe air and water serve two different functions - the air is what is compressed, and pushes the water out of the back end of the rocket.  The water, although basically incompressible, is what makes the rocket go.  Momentum is always conserved, so whatever momentum (mass times speed) the water gets going out the back is also imparted to the rocket in the opposite direction.  You can think of it as positive and negative added momentum, creating a net change of zero.  The rocket is usually a much lower mass than the water, so the speed it achieves in order to match the momentum is higher than that of the water.\n\nAfter the water and air are expelled from the rocket, gravity is the only remaining force; the rocket slows, reverses direction, and lands on the ground.
457644
It does indeed have a higher specific gravity than fresh water.\n\nPure water has a specific gravity of 1000 kilograms per cubic meter\n\nSea water (in general) has a higher specific gravity, on average it is around 1026 kilograms per cubic meter
919025
Let's clear up our terms a little bit.\n\nGravity only generally occurs between things of mass.  And it is pretty much independant of what the mass is doing.  And I say pretty much because there are things that can create or destroy mass... but in a general sense it all comes down to the mass.\n\nNow, as astronomical bodies form, they tend to get a spin.  Because of the conservation of angular momentum, things that suck up more mass tend to have more spin than others.  These are, however, tendancies, NOT necessities.\n\nCase in point - the Earth.  Because of the tides, the spin of the Earth is slowing down.  We used to have twelve-hour days millions and millions of years ago, but now they're twice as long.  Has this affected the force of gravity?  Not a bit.  The same mass is present, and it's causing the same amount of gravity.\n\nWhat your friend may be confused by is what is sometimes called centrifugal force (a physicist would probably just call it inertia, though).  Although gravity pulls us down to the centre of the Earth, the motion of spin carries us away from the centre, counteracting gravity.  This means if you take a tool to measure gravity near the equator, you'll get a lower reading then you will when you measure it at the axis.  The force of gravity hasn't changed at all, but the spin is creating another force that is mitigating gravity's effects.  On Earth, this force is pretty small, but it's concievable that it could amount to a huge amount on a fast-enough spinning object... say, a space station with almost no gravity, but which was spinning fast to simulate gravity but pulling out instead of in.\n\nSo in a literal sense, you are completely right.  Gravity has ONLY to do with mass (well, mass and distance).  In a squishier sense, your friend is sort of right, in that spin can change the APPARENT force of gravity in local areas and that objects with large gravities also tend to have large spins.\n\nHope that helps!
208514
Yes, anything with mass generates gravity.  Gravity will only effect things which have mass, so the fact that you are stuck down means you have mass, and thus gravity.