I'm no physics expert Joe. Just a very interested fan of a great subject. My answers are copied &pasted from a great website I have bookmarked which I frequent often as well as post questions on. I've found a couple of answers to earlier questions asked-
How is it that birds can sit on livepower lines all dat long,and not end up a Colonel Sandersspecial (Kentucky Fried Chicken)?
Actually, if we were to sit on a power line and not touch anything else like the birds do, we <u>would not get electrocuted! </u>The reason for this has to do with the fact that current, a flow of electrons, flows along a path of least resistance. The electrons want to get to where they are going in the easiest possible way, much like a person might walk on the sidewalk instead of the grass because it is easier. When a bird sits on a wire and the electrons reach the part of the wire where the bird is sitting, the electrons have two options. They could go through the bird's feet and encounter a large amount of resistance or they could go through the metal. All metals are conductors which means that electrons flow through them easily. Because it is easier to travel through the metal instead, the electrons don't go through the birds feet, so the bird stays safe.
The same thing would happen if a person sat on a wire and the electrons would go through the wire instead of through the person. If, however, the person reached out to a tree or anything else connected with the ground, there is a new path of lower resistance and the electrons would go through the person to the ground, electrocuting him.
Why is it that the liquid level remains the same when you pour ice cubes into a drink, after they have melted? Shouldn't the level rise once the ice has melted?
The water level willremain the same when the ice cube melts.
A floating object displaces an amount of water equal to its own weight. Since water expands when it freezes, one ounce of frozen water has a larger volume than one ounce of liquid water. A completely submerged ice cube weighing one ounce, for example, displaces MORE than one ounce of liquid water. The cube will rise until the volume remaining under the surface displaces only one ounce of water.
If you could remove the ice cube and leave a "hole" in the water where the cube used to float without disturbing the surrounding water, that hole would take exactly one ounce of liquid water to fill. Let the ice cube melt. Since it is now one ounce of liquid water, putting it back into the "hole" will exactly fill it and leave the remaining water undisturbed.
Raging Bulldog
