Blog 13

This past weekend I was watching Cast Away starring Tom Hanks.  I watched starting at the time when he was on the plane.  He was marooned on the island and was learning to survive by himself with no tools and modern equipment.  Then the movie flashed forward to a couple years later and it showed him catching a fish using a spear.  I thought that it was just Hollywood appeal because every time I moved towards a fish it darted away.  Bu that's because the fish could see me.  In the movie, Tom Hanks is far away when he throws the spear so the fish can't see him due to internal reflection.  The fish's angle of incidence if looking at Tom would be past the critical angle which means that everything the fish saw would be a reflection of underwater.  However, Tom could see the fish because his vision is moving from a fast medium to a slow medium which has no critical angle.  This was how he was able to spear the fish.

Blog 12

A couple of weeks ago, I was heading from Castle building to the Weinberg building.  It was passing period between period 6 and period 1 and it was a cycle 3 schedule.  This was the week before family fair and preparations were going on around campus.  I was late to class by a couple of minutes because I got held up in period 6, so when I was walking to Weinberg there were no students and it was quiet.  There was a forklift coming towards me carrying supplies and it was sounding its siren.  Everything was normal until I passed the forklift and then the pitch of the siren dropped significantly.  This happened because of the doppler effect.  When the forklift was moving towards me, its waves were close together making it have a higher frequency and pitch.  But once the forklift passed, it moving away cause the waves to be more separated decreasing the frequency and pitch.

Blog 11

Last week Thursday on March 10 the earthquake hit Japan.  The earthquake created a tsunami that hit northeastern Japan and spread across the Pacific.  Like every other major earthquake that occurs on the ring of fire, this past one generated a tsunami.  Once my mom heard about the earthquake and tsunami warning, she made my family evacuate since we live across the street from the ocean.  We were pulling out of the driveway when my mom told me to go grab a flashlight in case power went out.  I hurried upstairs and found my shake flashlight which doesn't require batteries which I thought was good in case we run out of batteries.  The flashlight doesn't need batteries because it can generate its own electricity.  When shaken, a magnet passes through a coil. The changing magnetic field that is produced creates a changing flux.  The changing flux induces a voltage in the coil.  The voltage makes a current which consequentially makes power to work the flashlight.

Blog 10: Power Outage

About a week ago when the big storm passed over the state, I was working on my physics project which was due the next day.  After hurriedly getting my other homework out of the way, I began to work on my project.  It was about nine o'clock and that was when the storm was concentrated the most on the island.  I could see lightning and hear the thunder and the heavy rain.  I found my flashlight in my room just in case the power went out, so I could find my way around the house.  The power did go off and I reached for my flashlight.  Unfortunately, it did not turn on, but thankfully the power was restored in about a minute.  Once the power was back on I opened up the flashlight to see the problem.  The flashlight was a mag-lite flashlight so the top needs to be twisted for the flashlight to turn on.  In the flashlight, I saw my problem.  A piece of the lens had come loose and prevented the flashlight from completely screwing in.  Since a closed circuit and a voltage difference is needed for electrical appliances to work, the flashlight did not turn on.  I fixed the lens piece and then the circuit could be closed and current could flow through the circuit and the light bulb.  The batteries provided the voltage difference and once the circuit was completed, I would be prepared in case the power went out again.

Blog 9: "It's Electric!"

Last week I got some new pajamas.  I got a long sleeve t-shirt and some silk shorts.  They are very comfortable and I sleep with them on every night.  When I wake up and go to the bathroom in the morning to change, I have to take off my shorts.  I noticed a couple of days ago that when I took off my shorts they made a crackling sound and I felt the hair on my legs move.  This was because my legs and my shorts became charged by friction during the night.  The charge that was created was due to skin and hair's tendency to become positively charged and although silk also becomes positively charged, its magnitude is very smaller.  When I took my shorts off, the extra electrons on the shorts transferred to my legs.  The movement caused the sound of the sparks and the extra electrons in my leg caused my hairs to stand on end.

Blog 8: Disc Sapce

I was working on my computer this weekend.  I had plenty of review to do to prepare for semester exams and spent a lot of time online.  However, everyone needs a break and after a couple of hours of working, I took one myself.  I just searched around my desk and I saw a small disc, the kind used in the mini DVD video cameras.  It contained a video that me and my friends took early in the first quarter for a class project.  After watching it and enjoying a good laugh, I put in a game disc to play a little video games.  I noticed that once I closed the tray my computer's fan began working harder and my computer got hotter.  I realized that since I inserted a bigger disc it had a higher moment of inertia due to its mass and distance.  This meant it required more energy to spin than the mini DVD disc.  Due to its bigger moment of inertia, my computer eventually returned to normal since it also takes more energy to stop the disc spinning.