Blog 9: Electric Fields

I remember that when I was a young lad in elementary school, there was something that made me a feel a bit uneasy when I climbed onto the playground.  Occasionally, when I would run merrily around in the playground, my hand would feel a sharp sting when I touched one of the metal bars of the playground frame.  For a while, I had believed that it was due to the sun heating up the metal to unbearable temperatures until it became so hot that it would burn your finger if you touched it.  However, as I matured and as my mental intellect skyrocketted, I discovered that it is actually caused by the phenomenon of static electricity and the transfer of electrons.  If our body becomes negatively charged due to static electricity, we have an excess of negatively charged electrons, and our body wants to give those extra electrons up.  When we make contact with a electrical conductor such as a metal playground bar, the excess electrons rush to the less negative bars out of our body.  The transfer of electrons from our finger touching the bar causes a shock.  Our body can become negatively charged through a number of ways, the most common being friction.  I believe that when I would slide down the slide, the friction between my pants and the slide transfered electrons from the slide to my body, giving me a negative charge.
 

Blog 8: Moment of Inertia

When I was playing mustang baseball, one thing that I had always used to do was to try and balance a baseball bat on the tip of my finger.  Initially I had thought it would be extremely difficult to do, but surprisingly, it was extremely easy.  For a while after that, I had always believed that it was easy for me to do simply because I was very talented at it.  However, when I saw that many other people could do it, I began to wonder why it was so easy, until this year in physics.  The mass of the baseball bat is distributed such that most of the mass is at the top half of the bat, while the bottem half of the bat (the handle) is extremely light.  I learned that because of this distribution of mass, the moment of inertia of the bat is very high, meaning that it is very hard for the bat to begin to rotate.  Because of the high moment of inertia due to the majority of the mass being far away from the point of rotation, the end of the handle of the bat, the bat is extremely easy to balance on a person's finger if they balance it on the handle side.