Why does a boat float higher in denser salt water of the sea than in a less dense fresh water of a lake?
108432
Boats do NOT displace more water than they weigh - the amount of water displaced is EQUAL to the weight of the boat. Salt water is heavier per cubic meter than pure water or fresh water, so a smaller amount of salt water would be displaced for the same weight boat. If the density of the solution was extremely high, as in mercury, the boat would appear to sit on top of the liquid.
902687
The density of pure water is 1.0\nThe density of ice is .92 (ice expands when it freezes, so the density drops)\nThe density of sea water is 1.025 (sea water is denser then pure water because it is salty).\n\nAn ice cube floating is a glass of water is 92% submerged (compare their densities.)\n\nAn ice berg floating in sea water is 90% submerged (.92/1.025)
561534
Your question is a bit ambiguous, but let's see if we can answer and clarify:\n\n(1) There is a lake with a certain amount of water, thus establishing a water level with respect to the ground.\n(2) There is a boat with a coin inside it on the lake. The boat sinks into the lake to a level that you can mark on the side of the boat.\n(3) The coin is tossed into the lake, thus reducing the total weight of the boat and this will cause the "water level" wrt to the boat to change, i.e. the "water level" will decrease a bit since the boat will have risen a bit higher from the water surface.\n(4) When the boat with the coin inside it is floating on the lake, the lake's water level wrt to the ground will rise a bit, because the boat has displaced the lake's water.\n(5) When the coin is tossed into the lake, the water level wrt to the ground does change, but we do not know how because now the lake's water is being displaced by the coin's physical volume, not by its weight, as it was the case when it was inside the boat.
194414
Water is denser than air and transfers heat more rapidly.
51008
The high concentration of salt in the Dead Sea renders the water denser than any other body of water. The higher the density of water, the greater your bouyancy.
303434
This Great Lake doesn't have tides like the ocean; however, periodically the water levels rise and fall by as much as one foot due to a phenomenon called a ‘seiche’ (SAYSH, a French word that means "to sway back and forth"). This happens when water piles up on one side of the lake because of wind or high barometric pressure and then shifts back to the other side. Small seiches occur all the time, but sometimes strong ones can cause ships to bang together in harbors, or leave them high and dry for a few minutes.
885671
DENSITY is the key.\n\nRemember, an aircraft carrier will float in water because it is less dense than the water.  To calculate density, divide mass - kilograms (m) by volume - cubic meters (v).\n\nPure water at 25 degrees Centigrade has a density of 998 kg/m^3 so any object with a density lower than this would float.  Higher would sink.\n\nInteresting note:  If you could find a body of water large enough, the planet Saturn would actually float in it since it is less dense.
855088
Wood floats in water becuase water is more dense (higher weight for the same volume) than wood. Boulders or rocks are much more dense than water so they sink. It isn't the total weight that's important but the density.
71290
Solid (frozen) water is lighter than liquid water.  Since low density materials float on higher density materials, ice floats on water.  \n\nSolids are typically poor condutors of heat, so ice forms an insulating barrier between the cold air and the warmer water below.  This insulating effect is what keeps lakes from freezing solid.\n\nIf ice was denser than water, ice would sink and liquid water would rise up to contact the freezing air above.  Even the deepest of lakes and rivers would freeze solid.  Life as we know it could not exist over most parts of the earth.\n\nIt is important to remember that most solids are denser than their melted (liquid) forms.  Water is very unique.  Since we cannot imagine life without floating ice, scientists are looking for water in the cosmos as signs of places that we, or other beings might be able to inhabit.
207343
yes and no, it all depends on your density in relation to the water. although it salt water its easier because its density is higher than freshwater. you can change your overall density in relation to the water by changing how much air you hold in your lungs.
278046
Depends on what the "mass" is (its density)!  If the mass is more dense than water, then the mass is heavier - if the mass is less dense than water, then the mass is lighter than water.  Ice is the solid form of water and it is less dense, therefore it floats.
792914
Yep.  If you put a 1000 ton boat in the ocean, the level rises just as if you put 1000 tons of salt water in the ocean.  Don't try to measure it though.
193750
This is due to the seawater having a greater heat capacity than the land, thus they heat and cool off at different rates, causing pressure differentials in the air above them. See the source for details.
684710
A piece of iron has a density greater than water. Thus it will sink when the weight of the volume of water displaced by the piece of iron is less than the weight of the piece of iron. If iron is shaped, or used to make a ship,  the iron ship will float if the total volume of water displaced by the part of the ship in the water weighs more than the total weight of the iron used to make the iron ship. Thus, the upward force of buoyancy is greater than, or equal to,the downward force of gravity and the ship stays afloat.\n\nThis is called Archimedes's principle of buoyancy and it is fundamental to the design of all ships and heated air balloons.TWH
698894
An object will float in water if its density is less than the density of water.  Solid steel is more dense than water so it sinks.\nA steel boat is hollow and filled with air.  Its average density is less than a solid piece of steel.  If this average density is less than water the boat will float.  Of course if the boat becomes swamped  (filled with water) then the average density increases and the boat sinks.
879719
They are actually not similar.\n\nWater, unlike most substances, becomes less dense when it freezes. This is why ice floats and (in a way) one of the properties of water that allows life as we know it to exist.\n\nEvaporation of sea water leaves behind solutes (salt, minerals, etc) that become more concentrated over time, increasing overall density of the water left behind (if it's not replenished with fresh water). This is why you see people float so easily on dead-sea type bodies of water (the Aral Sea, Great Salt Lake, the Dead Sea).
42743
It is called the dead sea because there is not alot of life in it...however the good news is its hard to get things to sink there.  The reason for both of these thigns is the salt content of the water, things cant live if teh water is to salty.  The reason things float is because water is more dense when there are other minerals and compounds in it, thats why its easier to float in the ocean, just think of the dead sea as an ocean with lots more salt\n\nhope this helps!!