Will the plane fly?
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Joined: Feb 2003
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From: Las Vegas
Originally Posted by Beerstalker
The plane will fly.
The water in the glass will stay equal with the top of the rim.
The water in the glass will stay equal with the top of the rim.
Just did the ice/water/glass test.........I'll be danged, the level looked to stay the same!!!
The reason that screws with my head is that if you have a frozen solid plastic bottle (like what you'd take to the gym) by the time it melts down, it's 3/4 or less full of water.
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From: Valley of the Sun AZ
Originally Posted by pchristman
The ice floats, because it (the water in the ice cube) has expanded, and the density of the cube is less than that of the water. Objects that float displace an amount of water equal in weight to the object. However, objects that don't float (the melted water from the cube) displace an amount af water equal to their volume.
Density is the amount of weight in the object. If I gave you four blocks that were the same size, but different materials they would all act differently.
1- Ice (Would float due to the air)
2 – Wood (would float due to the air)
3 – Aluminum – Would sink, but at a slower rate due to its weight
4 – Iron – Sinks like a rock due to its weight
On a side note, you can make ice cubes with little or no air encapsulated in it. You have to get the water to flow at a very, VERY slow rate down a rod and then into the freezer.
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Joined: Sep 2004
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From: Northern PA
The plane will fly. The conveyor is indeed a distractor. Think of the plane as sitting on a frictionless surface. It should actually take off more easily, since there is no drag from the wheels to overcome.
The melted ice does not raise the level of the water. Ice takes up more space due to its crystalline matrix, which makes water "expand" as it lines up in a rigid crystal structure. Once it melts, the molecules are free to assume a more tightly packed formation.
The melted ice does not raise the level of the water. Ice takes up more space due to its crystalline matrix, which makes water "expand" as it lines up in a rigid crystal structure. Once it melts, the molecules are free to assume a more tightly packed formation.
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I'm not so sure about entrapped air in ice. Water expands when solid air or no. It's a function of the molecular structer of water.
Ships float because they displace a larger mass of water than the volume of the ship. It is in effect like a balance scale, ship on one side, displaced water on the other. As long as the ship's volume displaces more water than the mass of the ship, it floats. The volume of the ship below water is the same mass of water as the mass of the ship.
If you had 1 gram of water and say it has a volume of 1 cm cubed (probably doesn't but keep the units simple). If you freeze that water the water expands and occupies say 1.2 cm cubed volume. It still has a mass of 1 gram. Place that cube in a cup that will hold 10 grams of liquid water you can then add 9 grams of water to the glass. the last gram is the ice but it occupies 0.2 cm cubed more space than the rest of the water. The water level is at the top of the glass and 0.2 cm cubed of ice sticks out of the top of the water. As the ice melts. the mass of the water that was ice does not change. The volume of the ice reduces and eventually the 1 gram of ice now occupies 1.0 cm cubed of volume. 1.0 cm cubed + 9.0 cm cubed = 10.0 cm cubed, the glass remains full to the brim without overflowing.
And the plane flies.
Ships float because they displace a larger mass of water than the volume of the ship. It is in effect like a balance scale, ship on one side, displaced water on the other. As long as the ship's volume displaces more water than the mass of the ship, it floats. The volume of the ship below water is the same mass of water as the mass of the ship.
If you had 1 gram of water and say it has a volume of 1 cm cubed (probably doesn't but keep the units simple). If you freeze that water the water expands and occupies say 1.2 cm cubed volume. It still has a mass of 1 gram. Place that cube in a cup that will hold 10 grams of liquid water you can then add 9 grams of water to the glass. the last gram is the ice but it occupies 0.2 cm cubed more space than the rest of the water. The water level is at the top of the glass and 0.2 cm cubed of ice sticks out of the top of the water. As the ice melts. the mass of the water that was ice does not change. The volume of the ice reduces and eventually the 1 gram of ice now occupies 1.0 cm cubed of volume. 1.0 cm cubed + 9.0 cm cubed = 10.0 cm cubed, the glass remains full to the brim without overflowing.
And the plane flies.
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From: Peoria, IL
Originally Posted by 76supercab2
I'm not so sure about entrapped air in ice. Water expands when solid air or no. It's a function of the molecular structer of water.
Ships float because they displace a larger mass of water than the volume of the ship. It is in effect like a balance scale, ship on one side, displaced water on the other. As long as the ship's volume displaces more water than the mass of the ship, it floats. The volume of the ship below water is the same mass of water as the mass of the ship.
If you had 1 gram of water and say it has a volume of 1 cm cubed (probably doesn't but keep the units simple). If you freeze that water the water expands and occupies say 1.2 cm cubed volume. It still has a mass of 1 gram. Place that cube in a cup that will hold 10 grams of liquid water you can then add 9 grams of water to the glass. the last gram is the ice but it occupies 0.2 cm cubed more space than the rest of the water. The water level is at the top of the glass and 0.2 cm cubed of ice sticks out of the top of the water. As the ice melts. the mass of the water that was ice does not change. The volume of the ice reduces and eventually the 1 gram of ice now occupies 1.0 cm cubed of volume. 1.0 cm cubed + 9.0 cm cubed = 10.0 cm cubed, the glass remains full to the brim without overflowing.
And the plane flies.
Ships float because they displace a larger mass of water than the volume of the ship. It is in effect like a balance scale, ship on one side, displaced water on the other. As long as the ship's volume displaces more water than the mass of the ship, it floats. The volume of the ship below water is the same mass of water as the mass of the ship.
If you had 1 gram of water and say it has a volume of 1 cm cubed (probably doesn't but keep the units simple). If you freeze that water the water expands and occupies say 1.2 cm cubed volume. It still has a mass of 1 gram. Place that cube in a cup that will hold 10 grams of liquid water you can then add 9 grams of water to the glass. the last gram is the ice but it occupies 0.2 cm cubed more space than the rest of the water. The water level is at the top of the glass and 0.2 cm cubed of ice sticks out of the top of the water. As the ice melts. the mass of the water that was ice does not change. The volume of the ice reduces and eventually the 1 gram of ice now occupies 1.0 cm cubed of volume. 1.0 cm cubed + 9.0 cm cubed = 10.0 cm cubed, the glass remains full to the brim without overflowing.
And the plane flies.
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From: Las Vegas
Originally Posted by 76supercab2
The water level is at the top of the glass and 0.2 cm cubed of ice sticks out of the top of the water. As the ice melts. the mass of the water that was ice does not change. The volume of the ice reduces and eventually the 1 gram of ice now occupies 1.0 cm cubed of volume. 1.0 cm cubed + 9.0 cm cubed = 10.0 cm cubed, the glass remains full to the brim without overflowing.
I agree with everything except why are you assuming the ice sticks up over the top??? While the ice "floats" to the top, it certainly doesn't float ON top of the water.
I actually did this test yesterday....(I know, get a life!!)the water, including the ice, was level at the top of the rim.
Using your theory of the ice taking up more room (which I agree with 100%) I fully expected the level to go down after the ice melted.....it didn't appear to, or if it did, I couldn't tell with the naked eye.
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Joined: Aug 2004
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From: Bangor, ME
Originally Posted by DOHCmarauder
Why? The plane will fly, no ands, ifs or buts.
Lift=Coefficient of Lift x Air Density/2 x velocity squared x surface area of the wing.
The Velocity of air over the wing in the instance of a plane standing stationary on a conveyor belt is 0. If you substitute a 150 mile an hour wind on the taxiway then the answer would be YES it would fly (have actually seen this in a Cessna 152 long ago during gale force winds).
Should also clarify what kind of plane, as something like a C-130 has an enormous amout of thrust induced lift as airflow from the Props goes right over wing, creating lift while not moving...A jet doesn't work the same way and thus no airflow over the wing while its stationary.
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From: Calgary, Canada
Originally Posted by Aztrainer
The ship weighs more than the water, but it floats because of the air.
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From: Calgary Canada
This thread is awesome!
EMB135Driver, The type of airplane doesn't matter here.
And we all understand how lift works. Everyone agrees that this imaginary airplane will need AIRspeed to ever create any lift.
I guess the easiest way to see what will create airspeed is this. Since the engines are pushing against the air, they will push the plane forward through the air. The conveyor belt doesn't matter.
I could do this all day, but I'm going to drive my 77 instead.
Have fun!
EMB135Driver, The type of airplane doesn't matter here.
And we all understand how lift works. Everyone agrees that this imaginary airplane will need AIRspeed to ever create any lift.
I guess the easiest way to see what will create airspeed is this. Since the engines are pushing against the air, they will push the plane forward through the air. The conveyor belt doesn't matter.
I could do this all day, but I'm going to drive my 77 instead.
Have fun!
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Joined: Aug 2004
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From: Bangor, ME
Originally Posted by DOHCmarauder
Why? The plane will fly, no ands, ifs or buts.
out of curiosity, do you fly?
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Originally Posted by furball69
Ship weighs more than which water? If you mean the water that the ship displaces, it weighs less than that water, which is why it floats.
Ever hear of a ship being referred to as 'displacing XXXX tons'. That's how the weight and size of the ship is determined. The volume of the hull is known. They measure how much of the hull is below the surface to know how much the ship weighs. As a cargo ship is loaded, it displaces more water and rides lower. Thus the scale on the hull of cargo ships. It indicates how much the ship is loaded.
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Originally Posted by EMB135Driver
So the second the plane lifts off this conveyor belt which is going exactly 180 degrees opposite the direction of "flight" at the same speed, what is the velocity of airflow over the plane's wing.....if your theory is correct and the plane were to take off at lets say 125 miles/hr...the instant it broke free of the conveyor belt and was airborne (remember the plane was stationary on the conveyor belt as the engines were providing enough thrust to keep the plane from moving forward or backward to a fixed observer), what speed would the plane be doing in the air? To stay airborne, it would have to accelerate instantly to an airspeed of 125 miles/hr to maintain flight...so unless you can generate 125 miles/hr airspeed while still on the conveyor belt, what makes the plane fly.
out of curiosity, do you fly?
out of curiosity, do you fly?
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Joined: Oct 2003
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From: Virginia Beach
Originally Posted by EMB135Driver
So the second the plane lifts off this conveyor belt which is going exactly 180 degrees opposite the direction of "flight" at the same speed, what is the velocity of airflow over the plane's wing.....if your theory is correct and the plane were to take off at lets say 125 miles/hr...the instant it broke free of the conveyor belt and was airborne (remember the plane was stationary on the conveyor belt as the engines were providing enough thrust to keep the plane from moving forward or backward to a fixed observer), what speed would the plane be doing in the air? To stay airborne, it would have to accelerate instantly to an airspeed of 125 miles/hr to maintain flight...so unless you can generate 125 miles/hr airspeed while still on the conveyor belt, what makes the plane fly.
Why does an airplane need wheels? To generate airflow over the wings? No. It needs them to allow it to roll down the runway, so the engines can generate airflow. Wheels are not connected to the engines on an airplane.
Now, if a ship were on a conveyor belt, it wouldn't really matter how much water it displaced, it would never be able to take off, and it wouldn't matter if the ice were melted or not!