Final_Exam_Essays



These sample essay answers were taken from exams given in 2012. The number in parentheses shows the score I gave it, on a 1-10 scale, with 8 points representing a 4.0/A, 6 points representing a 3.0/B and so on.

Please do not try to memorize answers; they are rarely as effective as when you are thinking about the best way to say it as you write. Instead, develop an outline of topics that need to be included, and use your understanding to build from that outline.

Crude Oil
(5) Crude oil is oil that has yet to be processed. In order to process it we heat it up at extreme temperatures in smelters. This makes it useful because it turns it into liquid and that is how we need it.

(6) Crude oil is the gas you put in cars or in your house. Crude oil in your cars is used for fuel. This fuel allows your car to move. Another example of where crude oil is used is in your house. In your house it is again used for fuel but it is used to keep your house warm not to move your house. Where does crude oil go before this though. The first thing it does is it get brought out from under the ground. One of the best places to find oil is the U.S. Most people wouldn't think that today though because we are importing oil from other countries. Also we don't have use are own oil and we should. After the oil is taken from the ground it goes to a refinery to be refined to the type of crude oil that you can use it in your car and your house.

(8) Crude oil is the "oil" that is drilled straight from the ground. This crude oil contains many molecules that we know that come from oil itself, such as gas, petroleum, etc. They way we process the crude oil to make it useful is as follows. We take the oil to a refinery, where it is burned to the point where it evaporates, and all the different molecules contained in the crude oil will separate into different pipes based on their density. The molecules become their own, no longer part of the crude oil. The evaporating of the crude oil is a physical change, so no new molecules are formed, because they were part of the original crude oil when it was first drilled.

Mechanical Advantage
(5) You could tell which was which by finding the mechanical advantage, and then you would know to use the one with the greater mechanical advantage. Examples of common tools that display a variety of mechanical advantages are levers, and pulleys.

(7) If one machine had twice the MA of another machine i could tell easily which one had the more MA. The reason i could tell would be which of the machines had the greater input distance. For example, If one machine had a small input distance and the other machine had a larger input distance, than the one with the larger input distance would have the greater MA. Input distance is the distance between the location of force input into the machine to the fulcrum. To get a greater MA, you would have to increase the input distance and this would mean that the machine with the larger input distance would be the one with the greater MA. This would influence my use of these tools greatly. The one with the larger input distance and larger MA would be my choice. That tool would be my choice because the tool with the larger MA is always the easier machine to use and makes your job easier. A large MA= easier to use. In the world today there are many tools with a wide variety of Mechanical advantages. Some tools with low mechanical advantages would be a toilet handle flusher, scissors, and pliers. Objects with larger mechanical advantages would be a car jack to lift tires and shears for cutting branches.

(9) If i had two simple machines and knew one had twice the mechanical advantage that the other had i could tell. For example if i had two wire cutters i would know that to get the mechanical advantage i would divide the length of the handle, from the fulcrum to the tips of the handle, by the length of the distance from the tips of the blades to the fulcrum. Whichever was greater would have the most mechanical advantage. For example if the blade to handle distance ratio for one was 1 to 5 inches and the other was 1 to 3 inches i would know that the first would have the greatest mechanical advantage. The one with less mechanical advantage i would use more for weaker things and thinner wires while for the first pair i would cut larger wires and thicker things. Many tools like screws, hammers, pulleys, and screwdrivers also have a variety of mechanical advantages.