There have been too many instances where
people in my engineering classes do NOT understand dimensional analysis or
tables. Sure, you may know how to do these
things, but you need to be AWESOME at these things. Some of you may not know what I'm talking
about. So let's have an introduction:
Dimensional
Analysis
Convert 12 miles to
meters.
If you buy a sweater that is $24, but 35% off, how much is the sweater?
Most people don’t know how to do these problems, at least not easily.
Tips for the trade:
A dimension is a
unit, which is like a number. You can reduce the following:
5/5=1. Well you can also do the
following: 
or 
.
or .
Think about other
possibilities. For instance,
.
.
Think about the unit
actually represents. Like area is
just a two-dimensional length. Volume is
three-dimensional length. Acceleration
is the time derivative of speed which is the time derivative of length. Okay, sure that was a little confusing. But think about the bigger picture. Here is a
cool video to show you what I mean: Imagining the 10th Dimension.
TABLES
Now about half (yes ½) of my upper division thermodynamics
class was spent teaching us how to read tables.
And still people failed that class.
Sure, thermo goes beyond reading tables, but if you can’t read a table
accurately, you are going to make silly mistakes on your tests. And tests are your entire grade!
Tips for the trade:
Read lots of tables!
Like train tables! I love sitting down and just looking at all
the different times and thinking of different possibilities. Another lame thing I like to do: read tables
in the backs of textbooks. It comes with surprises! For instance, I found the specific heat
for chicken and cake in the back of my Heat Transfer book. Now,
you can’t tell me THAT’s not interesting.
Use two pieces of
paper to track your points. Use one
horizontally and the other vertically.
It’ll also help so you don’t strain your eyes.
Mark your point
lightly with a pencil. This has
saved me many times. Sometimes I’ll look back over the test
and realize 1) my pencil point is in the wrong spot 2) I wrote down the number
wrong. It honestly helps you.
This whole blog post may seem like a "well, duh Serena." But I'm telling you! Even my supervisors at my internships have converted wrong! Be awesome at conversions, and then you can worry about the real "engineering."
SO TRUE! I cannot tell you how many times I've been in a chemistry class and the students don't know how to convert units.
ReplyDeleteUnit analysis has saved me so many times. I honestly think it should be a required separate class on its own. Even if I can't remember an equation, I rack up the partial credit by playing with the units and seeing how far I can get.
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