In this problem we must use Coulomb’s Law to find the charge of two spheres. You do not know the charge or each sphere, but you are given the total charge of both. You are also given the distance between then and the magnitude of the electrostatic force each exerts on the other. The solution

I stumbled upon this mesmerizing Java simulation of a liquid in a container made by Grant Kot. It is hypnotic and just plain beautiful. Click your mouse and drag it through the liquid to interact with it. Mr. Kot is a cellist who programs and studies fluid dynamics in his spare time. Read more about

Learning to write well requires practice, patience, and regular editorial feedback. It is a process that is never perfected, and I am certainly no expert. So, when students ask me how they can improve their writing, I point them toward two books on the subject that I always keep nearby. The first is The Elements

In the wake of the Fukushima nuclear disaster, xkcd posted this infographic to help clarify the doses of ionizing radiation people receive from various sources. Click on the image to be redirected to the large-format original. As a resident of West Virginia, I found it especially interesting that a person living within 50 miles of