Needle Compass

Out of the myriad of skills the Boy Scouts has taught me, I remember the compass. How to use it, when to use it, and of course how to make one. Now that I am older I kinda wonder why we would make a compass out of a needle when we could use the magnet that magnetized the needle to begin with. Probably because the magnet itself is too big to float on a leaf or more likely the needle is aesthetically pleasing as one side will have pointed end and the opposite would have a bulky end.
Just to open up old memories I have made a compass for myself. I took a labeled magnet of south and north. Rubbed/stroked the south end on the pointy end of the needle 50 times and 20 times more for good luck. Brought an outside leaf placed it gently in a bowl of water along with my needle. As suspected and experimented on for centuries the needle slowly moved toward north, that is the south polarity of the Earth. What occurred to my iron made needle was an aligning of the domains, which before were pointing any which way. After which to be sure it pointed in the right direction I took out my handy compass. It was the same. Science did not fail. IMG_0123

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Electric Driving

This past Friday I had the opportunity to spend the night out with friends just before the big Regional Science Olympiad Competition. Not the greatest idea, but it was refreshing. I studied for 2 hours after school with Dr. Lindsay for Circuit Lab, so I think it was a much needed treat. We decided to spend the night at Punahou Carnival as it would be our last in a long time depending on where we go for college. Don’t get me wrong, we do not like Punahou, think about it as us investing in the future of those Punahou students. We are promoting private education, so Punahou can provide financial support to those students in need.
Back to the topic at hand. Among the many rides that we rode we enjoyed “Scooter” the most. Apparently this the the real name as opposed to Bumper Cars, which it is commonly misnamed. The ride reminded me of a lab in Physics class. We learned about circuits, and the only way to have a functioning circuit is if it is if their is a potential difference. The cars only work if one end touches the top and the opposite touches the bottom this is the complete circuit from electric socket to motor back to socket. There is a potential difference between the roof and the floor, the electricity then is able to flow freely from one end to the next. I also noticed that the motor always had an initial jump or acceleration after pressing the “gas”, I would have to guess that among the components in the car there was a capacitor. The capacitor would stabilize the current that flowed through it and also give the car an initial kick after each press of the pedal.
It was another fun day with friends with physics applied. I didn’t take a picture of the crowd, but if I had it would have been a perfect example of current. When there are a lot of excited students at carnival and not a lot of room the current of the students or flow rate is unnaturally slow.

Jasmine and Lisa

Jasmine and Lisa