it sticks because water has a stickey molicule that sticks it togather it's h 2wich forms togather and o wich helps make water so reliable for manny things.
I would stick my mouth in the center of the glass and sip for about 15-20 seconds and then your glass won't be filled to the brim
Because cardboard doesn't contain water, it would be difficult to "make" water with cardboard. However, purifying water using cardboard can be done. Follow the link I have posted from a science fair that a boy had done just that! Apparently, after much research, I found his conclusions are correct. Here you go: http://www.usc.edu/CSSF/History/2004/Projects/J0822.pdf
According to Newton's Law of Inertia, the coin on the cardboard would tend to stay at rest when the cardboard is pulled slowly due to its inertia. As you pull the cardboard, the coin will initially stay in place relative to the glass of water due to its inertia. However, when the force increases or the cardboard is pulled quickly, the coin will slide off the cardboard due to the force exerted on it.
Water stick insects favor being on the surface of the water because this is where their food accumulates. Also, if they were under the water, they would not survive.
You would call strong cardboard 'cardboard'. It doesn't matter how strong it is, the cardboard is still cardboard. Even if the cardboard is extremely stiff, it is still cardboard, and there is no special name for it.
They would be way too heavy if you fill them with water.
water-made canals
No, a balloon filled with static electricity will not stick to metal if rubbed against your head. The static charge on the balloon and your head would not be strong enough to hold the balloon to the metal.
A wooden boat would float because it is designed to displace water and stay afloat. A waterlogged stick would likely sink because it has absorbed water, increasing its weight and reducing its buoyancy.
Usually - yes. Objects made of cardboard can float - at least until they become saturated with water. Even a sheet of cardboard will float initially. If the cardboard is coated with something that prevents the cardboard underneath from soaking up water, the object can continue to float for quite a while. Once it becomes saturated with water, cardboard will have more difficulty floating. Since it is made from paper - which derives from wood pulp - even when wet, it will tend to float rather than sink because wood is usually a bit less dense than water. Since it may not be JUST paper, it may depend on what else was added as to whether it will still float when soggy. It all depends on the average density. Note that as it becomes soggy, cardboard may tend to disintegrate - at which point it would just be a mass of mush rather than recognizable as cardboard.
The amount of water in a half-filled bath would depend on the size of the bath. Half-filled means the bath is filled to half its capacity. You would need to know the total capacity of the bath to determine the exact amount of water.
The sand puts weight on it and it makes in sink.