I’m teaching a junior level engineering course and the question was raised as to what units we should be using. Here’s my units rant:
I guarantee you will solve your problems faster, with fewer mistakes if you use base SI as your units system. It’s the only completely self-consistent unit system. Here are the steps:
1) Whatever units your problem is setup as, convert everything immediately to base SI: kg, N, s, K, Pa, m
2) Solve the problem in base SI, check for unit issues with a program like EES
3) Convert the solution back to whatever units you and your customer are comfortable with (the only reason you are not comfortable with SI is that we haven’t made it the standard in the US)
If you need even more reason to use SI units, or ever question your reasons for using SI, read the following article:
That’s what a convincing source looks like– The National Institute of Standards and Technology (NIST). The non-partisan federal agency tasked with establishing all standards of measure in the US. Brief excerpts from the 2 page article include:
1) The US is the only industrialized country in the world that does not use the metric system as its predominant system of measure.
2) The US began using the metric system in 1866 with congressional authorization
3) “The current effort toward national metrication is based on the conclusion that industrial and commercial productivity, mathematics and science education, and the competitiveness of American products and services in world markets, will be enhanced by completing the change to the metric system of units. Failure to complete the change will increasingly handicap the Nation’s industry and economy.”
Need more reasons? How about English units being the cause of the $655.2 million loss of the Mars Climate Orbiter
In short, if you or a faculty member are stubbornly clinging to solving problems in english units, you might as well be advocating use of a calculator (which is directly analogous to a typewriter), and requiring you put your homework on engineering paper (10x more expensive than copy paper, and near infinitely more expensive than electronic file submission). Times have changed and it’s time we evolve engineering education.