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.
Chemical weathering is what happens when rocks are broken down and chemically altered. Learn about the different types of chemical weathering, including hydrolysis, oxidation, carbonation, acid rain and acids produced by lichens.xidation. Another type of chemical weathering is oxidation. Oxidation is the reaction of a substance with oxygen. You are probably familiar with oxidation because it is the process that causes rust. So just like your car turns to rust through oxidation, rocks can get rusty if they contain iron.