Hole.
There is a central tube that goes up and then back down through a hole at the bottom. When water is filled up half way, the water level is the same on the inside of the tube. When the water level rises enough for it drop out through the cup, it creates a vacuum that sucks up all the water in the cup leaving it empty.
Water might disappear on a cup through evaporation. As the water sits, it begins to turn to a gaseous state and rises away from the cup.
No, it does not depend upon density, it is due to liquid nature of water which has a tendency to flow due to gravitational force.
You use a few cottonballs and pour the water through the cup fulll of cotton balls.
They had it in the past but, it will spoil easily and water will leak through the cup.
The boiling point of water is 100 degrees. However, the point at which paper burns is much higher than 100 degrees. When you boil water in a paper cup, all of the heat is transferred to the water, not the cup. When the water starts to boil, the paper stays unburnt. After the water has boiled through, there should be a small black mark on the base of the cup which can be easily removed.
Energy is transferred from a cup of boiling water through convection, conduction, and radiation. Convection causes the hot water at the bottom to rise, transferring heat to the cooler water at the top. Conduction transfers heat from the water to the cup, and radiation emits heat in the form of infrared waves.
True
they cup their hands so that no water go through you hand making the force increased
you need a cup. it should be one you can see through. then, you fill it about 1/4 of the way with water. cover the top of the cup with foil of plastic wrap, then heat up the cup. the water will evaporate into the cover of the cup, and form a cloud before raining down!
If a cup of water is dropped, the water will tend to stay inside the cup momentarily due to inertia. However, once the cup hits the ground and stops moving, the water will then spill out of the cup due to the lack of support from the container.
When water is poured into a transparent cup with a coin at the bottom, the light gets refracted as it passes through the water and into the air, causing the coin to appear raised and no longer hidden by the water. This phenomenon is called refraction and it makes the coin visible even though it's at the bottom of the cup.