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 involves the change in the composition of rocks, often leading to a 'break down' in its form. This type of weathering happens over a period of time. The types of Chemical weathering are: Dissolution: This occurs when rainfall is slightly acidic and gases in the air are added to it. This consequent mix can cause solution weathering of rocks. Hydration: Hydration is a form of chemical weathering that involves the rigid attachment of H+ and OH- ions to the atoms and molecules of a mineral. Hydrolysis: This is a chemical weathering process affecting Silicate minerals. is a chemical weathering process affecting Silicate minerals. In such reactions, pure water ionizes slightly and reacts with silicate minerals. Oxidation: This occurs within the chemical environment and makes the rocks soft.