much does petrified wood weigh? Answer...
OK, first, we've have to decide how large the piece of petrified wood is, because like anything else (cars, a sack of potatoes, kids) a big one will weigh more than a little one. To help get around this question of having to ask the size of the rock (or whatever) each time, scientists use a measurement called specific gravity, that allows us to compare different materials. To choose a few materials for comparison, water has a specific gravity of 1.0. Petrified wood (usually composed of the mineral quartz) would have a specific gravity of 2.65, so it is a little more than 2 1/2 times the weight of an equal amount of water. Gold has a specific gravity of 19.3.
can a rock become parts a car? Answer...
To make this a little more useful, imagine that you have a plastic container the size of a common brick (2 1/4 inches x 4 inches x 8 inches) and fill it with water. It would weigh a little more than 2 1/2 pounds. A piece of petrified wood the size of the brick would weigh nearly 7 pounds. And a gold brick would weigh about 50 pounds. Don't you wish you had that!
Most common rocks will have a specific gravity fairly close to that of the petrified wood used as an example. Pumice, a type of volcanic rock that is full of air bubbles, has a specific gravity less than 1—it will float on water. Most metals, especially gold, have much higher specific gravities. That's what enables us to recover gold by panning.
Every chemical element that occurs naturally on earth can be found in a rock somewhere (there are a few man-made elements, but they don’t count here). Rocks that are rich in certain elements can be mined and the elements separated by various techniques. Sometimes this is fairly easy (and therefore relatively cheap); for example, rocks containing copper minerals can be mined, ground finely, and the copper-bearing minerals can be separated by a process call flotation. These mineral particles can then be smelted (heated until they are molten) and the copper (and a few other elements) are separated as metals. In this process, US mines will typically produce 6-10 pounds of copper for every ton of ore that is processed. Other elements are not so easily separated from their host minerals, and require much more extensive treatment to be recovered, making them more expensive, particularly if their concentrations in the original rock are very low.
causes an earthquake? Answer...
So, once we mine and separate the stuff we need from rocks, how much of a car is made of rock materials? Nearly all of it! The most abundant metals will be things like steel (mostly iron with small amounts of things like carbon, tungsten, molybdenum, nickel, and others) for the frame, aluminum, copper for wiring, zinc for rust-proofing, chrome to make shiny trim.
The rest of the car is mostly plastics. Where do plastics come from? Most are made from petroleum products---more stuff that is recovered from rocks, although it is usually pumped and not mined. However, the materials to make the plastics are relatively expensive and by themselves do not always have the properties that are necessary to make a useful product. So, certain minerals may be ground up and added to the mixture. This serves two functions---the minerals are fairly cheap and they can change the properties of the plastic. In the industry, these minerals are known as fillers and extenders. Some of the more commonly used minerals are feldspar (the stuff that makes up about 70% of a typical granite), calcite (the mineral that makes limestone), clays, and talc.
So, without the materials produced by mining and petroleum geology, we would probably have to build our cars out of wood. This was common a hundred years ago; they were pulled by horses and were called wagons.
We feel an earthquake when seismic waves travel through the ground beneath our feet. Seismic waves travel through rocks in the earth’s crust much like ripples spread across the surface of a still pond after dropping in a rock. A cork floating on the pond will bob up and down when the spreading ripples pass beneath it. Although seismic waves in the earth travel much faster than ripples on a pond (and have some other fundamental differences also), it is the passage of seismic waves that causes the shaking motion we feel as an earthquake.
Sudden slippage along fractures in the earth’s crust (faults) causes seismic waves to form, which then radiate away in all directions. The greater the amount of slippage along a fault, the stronger the seismic waves. Like other forms of energy that travel as waves (sound and light for example), seismic waves lose energy as they spread out through the earth away from their source. This explains why damage caused by a large earthquake is generally greatest Closer to the epicenter; the seismic waves are stronger Closer to where they originate.