[- Air -]The Air around us is not weightless. In fact, it can be weighed almost as accurately as iron or lead. A column of Air 1 inch square and 600 miles high, for instance, weighs approximately 15 pounds, about twice as much as an average newborn baby. This weight is what creates the phenomenon known as "atmospheric pressure."
[- Elements -]Ten of the 105 known Elements had been discovered and were in use in prehistoric times: gold, silver, lead, iron, copper, zinc, tin, sulfur, carbon, and mercury. The largest individual contribution to the table of Elements was that of the nineteenth century English chemist Sir Humphrey Davy, who identified boron, barium, calcium, potassium, sodium, and strontium in 1807 and 1808. He also demonstrated that diamonds are composed of pure carbon and discovered the hilarious properties of nitrous oxide --"laughing gas."
[- Sodium -]If the chemical Sodium is dropped in water and a match is taken to the mixture, it will immediately and violently ignite. If Sodium is immersed in a pot of kerosene, however, it will not burn at all.
[- Sound -]Sound travels fifteen times more swiftly through steel than through air.
[- Theory of Relativity -]According to the Theory of Relativity, the mass of an object increases with its velocity. In nonscientific terms, this means that things get bigger as they move faster. The process has been demonstrated in laboratories. In several experiments, objects accelerated to 86 percent of the speed of light have doubled in weight. The theory also postulates the rather incomprehensible notion that given enough speed, an object will become as large as the universe itself.
In physics, mass is just simply locked up energy. We call this type of mass, ‘inertial mass.’ Essentially, inertial mass is the amount of resistance that a physical object has to any change in its motion (this includes the resistance that a body has to acceleration or to directional changes). According to the theory of relativity, gravitational mass is always the same as inertial mass. However, when we speak of an objects mass increasing due to acceleration, we are really talking about its inertial mass increasing. So when we think of mass as energy, we can begin to understand why an object will increase its ‘mass’ as it speeds up. As an object increases in speed, so does the amount of energy that it has, this energy is what we refer to as ‘the increase in mass’ (just remember, this is inertial mass).
[- Volume -]A pipe 2 feet in diameter will allow four times more fluid to pass through it than a pipe 1 foot in diameter-the Volume of a pipe varies as the square of its diameter.
[- Water Pressure -]If you punch a series of holes in a paper cup filled with Water, the Water will squirt out farthest and fastest from the lowest holes. The reason is that Water Pressure is greatest at the bottom of the cup. For the same reason, dams are made thicker at the bottom than at the top.