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Showing posts from September, 2013

The Misconception of Heat Unravelled

Most books define heat as if it were a form of energy. Heat transfer is dealt as the transfer of heat from one control volume to another control volume. Nothing can be farther from the truth. Not only does this kind of definition or representation give a false intuitive idea to the newbie, but it also causes confusion since the person would notice that something doesn't seem to fit in when he/she looks at the thermodynamic equations.

     Before I had my College Physics classes, I was a victim to this admittedly. I thought heat was transferred from one point to another and whose abundance was dependent on temperature. The first time I've read of a warning that this perspective was wrong was when I was doing advanced readings a few months before the start of classes (that is, the classes which include College Physics - somehow, reading the materials over the summer seems to help make things easier to understand). It said that a popular convention, and an extremely erroneous…

Calculator Techniques for the Casio FX-991ES and FX-991EX Unraveled

In solving engineering problems, one may not have the luxury of time. Most situations demand immediate results. The price of falling behind schedule is costly and demeaning to one's reputation. Therefore, every bit of precaution must be taken to expedite calculations. The following introduces methods to tackle these problems speedily using a Casio calculator FX-991ES and FX-991EX.


►For algebraic problems where you need to find the exact value of a dependent or independent variable, just use the CALC or [ES] Mode 5 functions or [EX] MENU A functions.


►For definite differentiation and integration problems, simply use the d/dx and integral operators in the COMP mode.


►For models that follow the differential equation: dP/dx=kt and models that follow a geometric function(i.e. A*B^x).

[ES]
-Simply go to Mode 3 (STAT) (5)      e^x
-For geometric functions Mode 3 (STAT) 6 A*B^x
-(Why? Because the solution to the D.E. dP/dx=kt is an exponential function e^x.
When we know the boundary con…