Driving on the 87 Octane yields 20 mpg so the driver is able to pass 200 miles for $31.00 dollars and the cost per mile will be $0.16. The example above is simplified but shows that even though the entry cost is lower and in the end, the gas will end up costing more.
Weathering of rocks is caused by chemical and mechanical means, and the types of weathering are therefore generally classified as chemical or mechanical (also known as physical).1  Slightly acidic rainwater can react with rock surfaces, dissolving them over time.ockhound. Weathering of rocks is caused by chemical and mechanical means, and the types of weathering are therefore generally classified as chemical or mechanical (also known as physical). 1  Slightly acidic rainwater can react with rock surfaces, dissolving them over time.
This process can be further subdivided into two categories: physical/mechanical weathering and chemical weathering. Chemical weathering refers to the processes by which rocks react with the atmosphere to form new substances. These reactions can alter a rock and transform the rock into sand, clays, and other minerals.CHEMICAL WEATHERING. Like mechanical weathering, there are several different types of chemical weathering.One type is oxidation, the reaction of oxygen with iron-bearing minerals in rock. In an oxidation reaction, the iron atom loses electrons and precipitates as another mineral.his process can be further subdivided into two categories: physical/mechanical weathering and chemical weathering. Chemical weathering refers to the processes by which rocks react with the atmosphere to form new substances. These reactions can alter a rock and transform the rock into sand, clays, and other minerals.