Author Archives: mathscinotes

Air Rifle Math

Posted on 3-February-2014 by mathscinotes

Introduction I received an email this weekend from a dad struggling to help his son with a project involving aerodynamic drag and BB gun. I did some quick calculations which I document here. I will try to look at pellets … Continue reading →

Posted in Ballistics | 5 Comments

Proofs Without Words

Posted on 1-February-2014 by mathscinotes

I love proofs without words. Usually, I see them in discussions of mathematical concepts like the Pythagorean theorem (examples). While reading about home construction at the Journal of Light Construction, I saw a nice graphical look at the difference between the gross margin on a product and the markup on a product. Continue reading →

Posted in General Mathematics | Comments Off on Proofs Without Words

At What Fuel Tank Level Should I Refuel?

Posted on 1-February-2014 by mathscinotes

It is cold in Minnesota right now and I hear the local motorheads warning people not to run their gas tanks down to empty. During winter, I hear this warning because of concerns that water vapor in the gas tank may freeze and cause the vehicle to stop. I also hear concerns about running on a low fuel tank during the heat of summer because the fuel is need to cool the fuel pump, which is often mounted in the tank. Some folks also say that there is corrosion at the bottom of the gas tank that get sucked into the fuel pump when running the tank near empty. Continue reading →

Posted in General Mathematics, Personal | 3 Comments

Radiation Exposure from Cigarette Smoking

Posted on 25-January-2014 by mathscinotes

Quote of the Day I write a lot of programs and I can't claim to be typical but I can claim that I get a lot of them working for a large variety of things and I would find it … Continue reading →

Posted in Health | 4 Comments

Minnesota Winter Turns a Corner This Time of Year

Posted on 22-January-2014 by mathscinotes

We are going through a some very cold weather now in Minnesota. During late January, I start to daydream about warm weather. While daydreaming about going to my lake cabin today, I started to wonder when the average daily temperature … Continue reading →

Posted in General Science | Comments Off on Minnesota Winter Turns a Corner This Time of Year

Excellent Video on Breaking the Japanese JN-25 Code During WW2

Posted on 19-January-2014 by mathscinotes

Those of you World War 2 history buffs may find this video lecture on the breaking of the Japanese naval codes. I have read a number of books on the topic, but I did not know that so much work … Continue reading →

Posted in History of Science and Technology, Military History | Tagged , , , | 1 Comment

Why Bother with Nitrogen in Tires?

Posted on 19-January-2014 by mathscinotes

Every Friday afternoon, the hardware and software engineers sit down in our lunch room and chat about what occurred during the week. The discussion is always lively and includes management and engineers. It is my favorite time of the week at work. This week we discussed why automotive shops put "dry nitrogen" in car tires – I am pretty sure all compressed nitrogen is dry because of the way it is processed. Continue reading →

Posted in General Science | Tagged , , , | 1 Comment

Very Cool Wind Maps

Posted on 16-January-2014 by mathscinotes

US Wind Map US Wind Map World Windmap World Windmap

Posted in General Science | Comments Off on Very Cool Wind Maps

Radioactive Banana Math

Posted on 16-January-2014 by mathscinotes

I have been reading about the hazards of space travel to Mars. During this reading, I occasionally see references to space radiation hazards in terms of Banana Equivalent Dose. I find this a strange unit. Then today I read a blog post by Anne Marie Helmenstine that discussed how bananas are slightly radioactive. I liked her discussion and I thought I would go through the math here. Continue reading →

Posted in General Science | 2 Comments

Funny the Little Things that Children Remember ..

Posted on 14-January-2014 by mathscinotes

This weekend, my oldest son recalled how we would spend Saturday morning watching Mystery Science Theater 3000 (MST3K) . All three of us would be laughing the whole time. There is no sound as wonderful as that of children laughing. We still talk about how fun it was to watch Japanese monster movies on MST3K. As far as I am concerned, that is the only way to enjoy Godzilla and Gamera. Continue reading →

Posted in Personal | 1 Comment