Blog 9

On Thursday night we had the Iolani Fair 2011 kick-off meeting!  Before the festivities began, our executive committee helped out with decorating the student center.  One of our jobs was to tie the balloons together and attach them to the tables.  We also got to play with some of the balloons ;D.  Scott kept trying to make people’s hair stand up by rubbing the balloon against their hair and pulling the balloon away.  Now, how on earth does this all relate to physics?!? Well, in physics we’ve been learning about charge and static electricity.  When Scott rubbed the balloon against my head, he was creating a charge by friction.  Also, when he tried to stick the balloon to someone, only the rubbed side would stick because rubber is an insulator and does not conduct electricity well.  Due to this trait, the electrons remained concentrated on one side of the balloon.

Blog 8

Today as I stared into the computer contemplating on what I should write my physics blog about…I heard the garage door open as my mom pulled into the driveway.  Oh my goodness! I thought, CARS ILLUSTRATE ROTATIONAL DYNAMICS!  The wheels of a car rotate, exhibiting rotational dynamics qualities.  In physics we learned that rotational inertia is equal to the mass times radius squared.  Because my mom’s van has a huge mass, it has a very high rotational inertia which means that it is harder to start and stop rotating.  I notice this a lot when I drive because my dad has a very small Rav4, as opposed to my mom’s Sienna.  When I drive my dad’s car, I don’t have to step on the breaks as hard as I do in my mom’s because the rav 4 is lighter and therefore has less rotational inertia, and is easier to stop.  Cars do not only have regular kinetic energy causing them to move, but rotational inertia as well! (Because the wheels are rotating AND moving forward)! Wooohoooo!