Circuits

While I hung out with Robbie this weekend, he drove his mom's car. However, he couldn't drive the car at night time because one of the headlights burnt out, so he had to switch cars to drive me home. Anyways, I found this is related to exactly what we are learning about in Physics class. A circuit must be complete in order for things such as light bulbs to function properly. As shown in this picture, the light bulb in the headlight does not work because the filament, that once connected the circuit in one path of traveling electrons, burnt out, so the circuit is no longer complete. Even though the car battery is still working to light the other lights on the car, that one headlight does not work because of the unclosed circuit.

Voltage & Extra Credit

This weekend for the BJ Penn fight, we had a bbq. Everyone brought all different types of foods. Anyway, while I was watching my dad grill all the meat, I noticed he had to just push this small button to fire up the whole grill. This made me wonder how one small button can start up the gas grill. Then, I realized the button was a electronic ignition and that it had a small voltage duracell battery powering the button. We just learned that voltage equals potential energy over charge and that it is a ratio. Since charge is measure in coulombs, there are a lot of electrons involved in lighting a grill. Even though a small dry cell battery was used, it was able to light the grill. I read that a bbq lighter uses something called piezoelectricity to generate a nice spark that lights the grill. Piezos are some kind of crystals. When you apply pressure to them, you get a charge separation within the crystal and a voltage across the crystal that is sometimes extremely high.




For this experiment, I tried it many times. It wouldn't work on myself, my mom, my sister, or Blake, so I finally tried it on one of my dogs, Chloe. With Chloe, I could see how the charge balloon made the water bend a little bit. The bending of the water can't be seen very well in the video, but if you listen, you can hear the difference as I bring the balloon closer and farther to the faucet water. Since the balloon received electrons from Chloe by friction, it changed from being neutral to being negatively charged. Water is made up of polar H2O molecules, so when it came closer to the balloon, the positive charges in the water separated from the negative charges and attracted towards the balloon, causing it to bend towards the balloon. My sister and I are going to try this again with a different type of balloon and hopefully it will be more evident.