Balloons

Graduation is in about a month~ and I saw on the news a few days ago that HECO was teaching kids at an elementary school that metallic balloons can cause power outages.

When metallic balloons fly up into power lines, the balloon may come into contact with the line at more than one point.  Since the balloons have low resistance, charge flows easily and the current is high.  The high-voltage lines can short-circuit, which causes the power outage.  Certain types of ribbon can also cause short-circuiting.  To prevent this from happening, balloons have weights tied to the end of the ribbon most of the time.  The weight of the balloon weight is greater than the upward tension (caused by the balloon due to the low-density helium inside it).

This might not be too great for power lines:

Balloons! Have a song ~

I’ve always wanted to dress up in one of those costumes for Halloween.  I love the huge gloves :D

Fish Leong!~

I can actually understand most of this one… O__o Haha.  I like her voice :)

A bug

I think I just killed a bug… I’m not really sure though, since I can’t find him.  Anyway, he was flying around in front of the laptop screen.  When he flies, lift helps him stay up in the air, and air resistance goes against the direction he is flying.  And when I squish him with my finger, I exert a force.  The pressure exerted on his body is equal to the product of the force I exert and the area of his body that is exposed to my finger.  His internal organs are not strong enough to withstand the pressure that I exert on his body.  And then he is flattened and his innards spill out… ew.  That part is not so good.  But I can’t find him anyway, so it doesn’t really matter this time.  When he falls from the side of the computer screen, his initial velocity most likely is neither entirely horizontal nor vertical.  Defeated, he travels in a parabolic arc.

Here’s a picture of him:

Pearl Harbor

On Friday, we went to Pearl Harbor.  Some areas of the water have a thin film of oil floating on the top, and when light hits the thin film, a rainbow can be seen on top of the water.  At the air-oil interface, the light reflects and undergoes a 180 degree phase change.  At the oil-water interface, light that has refracted reflects with no phase change.  The phase differences due to the differences in path length of the light results in constructive and destructive interference. Variations in the  thickness of the film also affect the light interference.

There were random splotches of color in the water ~ It looked something like this:

My camera wasn’t working too well that day…

Different colors appear because the light that hits the water is not monochromatic.  Instead, it has lights of many different wavelengths.  As the waves in the water go up and down, the angle at which the light hits the thin film changes, and the thickness of the thin film probably changes as well, causing the colors to change.

Gummi bears

Today at math team, no one brought real food, besides a bag of grapes :[

Instead, we had two large containers of gummi bears, some sour strawberry belts, a bag of cookies, and oreos.

Woo-kie!  Woo-kie!

After finishing his worksheets, one of the seamen decided to entertain himself by bouncing a gummi bear on his paper plate.  First, the gummi bear rested on the plate, while he applied an upward force on the gummi bear by quickly moving the plate up.  This upward force is greater than the weight of the gummi bear.  As the gummi bear leaves the plate, it travels in a parabolic path.

(Yeah, projectile motion and force are old topics… let’s just pretend I’m reviewing for the AP exam XP)

Later, the gummi bear lands on the plate, and when he caught it, he sort of cushioned its landing, but also applied upward force on it again. The gummi bear experiences a change in momentum, which is impulse.  In the collision between the bear and the plate, momentum is conserved.

I don’t have a picture, so here’s a Paint picture.  It’s been a while, so my (originally few) skills are a bit rusty >_<

In reality, the gummi bear does not  travel in an s-shaped path.  Also, you can’t really tell, but he has a face.

Window tinting

Over spring break, my dad decided to tint the windows so that the sun shining in wouldn’t damage our floor.  Also, the window film is supposed to reject about 72% of heat from the sun.  The window film is applied on the inside of the window, and it reduces the amount of infrared and ultraviolet radiation that passes through.  The tinted glass is darker than the untinted glass and also allows less visible light to pass through.

We still haven’t finished… Another week of spring break would have been good… and this week was pretty stressful, too… D:

In the second picture, you can also see that the window reflects some of the light from the inside of the house.  At night, the window tinting almost looks like a mirror.  Although some light from outside does pass through the window, there is much more light from the inside of the house that reflects off of the window tinting. I couldn’t get a good picture of it at night though.