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.
Weathering Process. The weathering process occurs when rocks are exposed to the hydrosphere (water) and atmosphere (air).  These agents can change the physical and chemical characteristics of rocks.  As rocks are broken down (weathered), they can be classified as different types of sediments, which are: o boulders, cobbles, pebbles, sand, silt, clay, and colloids. See page 6 of the Earth Science Reference Tables explains the sizes of each of these sediments.