marathon

Yesterday I started the day off extra early to help hand out water to thousands of marathoners. When we got to Triangle Park it was 3:30 and we all began to pour gatorade and water into cups. We broke up into groups of three or four and manned a table. All of the groups then started to stack their five layers of cups, trying to finish faster than everyone else. Everyone was almost done with their first layer when the water stopped working! We had a bunch of hoses attatched to a fire hydrant, and all of them stopped flowing. This made us all kinda nervous since our only job as a thirst aid station was to provide the runners with water/gatorade. Then, after a few phone calls, a Board of Water Supply truck arrived and saved the day. He had to "open up" the fire hydrant or something. But to do this he needed a long metal thing which helped him to provide torque...PHYSICS!! Torque is a force that causes or opposes rotation. In this case, it caused rotation and depended on force and the lengeth of the lever arm. The guy had a hard time at first, but he solved this problem by increasing the length of the lever arm...he increased the distance between his hand on the metal thing and the top of the hydrant. I was amazed how common an application of torque could be and how much easier it can make things. I tried to take a picture of this great display of physics, but the hydrant was right next to a reflective fire orange cone, which was the only thing that really showed up in the picture...but you can kinda see the man and fire hydrant if you look closely. The actual running part of the marathon also related to physics. For example, as the runners ran on the road, they exerted a force (mg) downward as the road gave them a normal (n) force upward. Also when we stacked our cups of water/gatorade, I witnessed center of mass. Of course, my friends and I had no problems stacking our cups without them falling, but some of our sisters stacked cups on the cardboard without any cups below them, causing them to fall. Here are some marathon pics. The one with the gatorade cups is from last year...I didn't get a chance to take a good one yesterday with all of the rain. So here's to great physics and all of those brave marathoners!

lightning BOLT!

All of the rain this Saturday was crazy! Our soccer beach run was cancelled (shucks ;) and instead I spent the day giving admissions tours, going to the movies, and celebrating my friend’s 18th birthday. But the rain reminded me of a huge storm my family and I got caught in this summer. Apparently freak thunderstorms are common in Chicago and the rest of the Midwest, but it definitely was an experience for us. Thunder and lightning is caused by, “the difference in charge between the thunder cloud and the foreign surface, such as a different layer of the cloud or the ground.” Normally the cloud gains a positive or negative charge and when the difference between the two regions reaches a certain point, the air between the charges breaks down, allowing the two surfaces to form a circuit and discharge. The first step in formation of lightning is the gathering of charge in the clouds (Physics of Electromagnetism). As the negative charges collect at the bottom of the cloud, the negative forces in the ground move away from the surface. The negative charges from the cloud then connect with the positive forces on the ground, creating a streamer of light…LIGHTNING! The heat created in the air then quickly expands, forming thunder; which is why you see lightning before you hear the thunder. Taller objects generally lead to a more condensed electrical field, making them more susceptible to lightning. In fact, during this storm, the Sears Tower, the tallest building in the Chicago skyline (and North America!) was hit by lightning. The Sears Tower actually gets hit by lightning quite often, thousands of times each year, which is why it has a lightning protection system. Here is a video and picture I took from my hotel room during the fabulous lightning display. The lightning went on all night, even when the rain stopped—embodying perfect physics the entire time.

fishing for physics

Last weekend a few of our families got together and went to the beach to relax and go fishing—it was really fun! The fishing definitely reminded me of physics. As we cast the lines, I saw motions which resembled parabolic curves. However the patterns were not totally accurate probably because of air resistance and drag. I also thought of mass and friction because of the lead weights we added to the lines. Although we couldn’t actually see the weights and hooks underwater, the mass of the weights created friction with the sandy bottom. This frictional force was greater than the force of the current, allowing the weights to stay still. Tension was the next thing that came to mind. As the fish started to bite, I could see an increase in tension in the lines, making it hard to reel the fish in. In the end we caught a bunch of stick fish, moi, white eels, and some other cool fish. I didn’t get any pictures of our catches, but here are a couple of us at the beach…I think the black things are swans.

first quarter reflection

This past first quarter of physics has been FUN, but also confusing to me. I think the hardest part, for me, is the tests. When I take my tests, I forget certain concepts or I start to second guess myself. Some of the homework assignments have also been challenging because sometimes I can’t solve all of the problems. I’ll start off by writing down all of the givens and try plugging the numbers into equations, but I just get stuck. On some nights I’ll try to solve the same problems for about an hour, but still end up having to get help and finish it the next day. But aside from the tests and homework, the labs are something that I can more easily understand. I enjoy doing the labs and I think that by visually being able to see the concepts that we are learning, I’m able to understand better. This past quarter has been fun and I think that physics is really interesting, but at the same time has been more challenging for me than all of my previous science classes. My goals for this course are to better prepare myself for quizzes and tests. I also hope to come in for help more as soon as I need it and to practice on some of the other problems in our text. But up until this point, even though I’ve been trying hard, physics has been one of my harder classes and I’ve been pretty confused, like Simba.

projectile motion

This weekend I went to Waimea Bay and suddenly saw physics!! In this picture, a man is jumping off of the BIG rock in the bay, displaying a beautiful projectile motion. Our book defines projectile motions as movements determined by an object’s initial velocity and the constant acceleration of gravity. This motion can be broken up into two vectors, horizontal and vertical. In this case, the man doing the jumping is the projectile and the only force acting on him is gravity. The man starts his leap by jumping off the rock horizontally. His horizontal velocity isn’t affected by gravity and remains constant throughout his jump, but gravity does affect his vertical motion which accelerates him towards the water. As he moves through the air, this vertical (y) velocity becomes increasingly negative (he is accelerating at 9.8m/s2 in the negative direction) until he hits the water below. Projectile motions…very fun :D

Bowling

This weekend while at bowling practice, I realized that bowling has a lot to do with friction and speed. Friction is defined as "a force that resists the motion of one object sliding past another." In bowling, these two objects are the bowling ball and the lane. The amount of friction between these two objects depends on how much the lane is oiled and the weight of the ball. A lot of oil will result in less friction and a smaller decrease in ball speed. On the other hand, a less oiled lane will result in more friction and a greater decrease in ball speed. In addition, a heavier ball will incur greater friction, and a lighter ball, less friction. Too much friction isn't always good becasue it can change the path of your ball, but at the same time it allows your ball to hook. Less friction will allow your ball to travel in a straighter path. Friction is very important to bowling.

the bean.

This summer while my family and I were in Chicago, we visited Millennium Park. One of the main attractions there is the Cloud Gate, but pretty much everyone knows it as “the bean.” The sculpture, created by artist Anish Kapoor, was inspired by a drop of mercury about to hit a surface and serves as a gate to the inside chamber. It stands about three stories high and weighs 110 tons. The bean’s seamless appearance and strategically placed curves allows its visitors to see the city through uniquely warped reflections.
As I viewed myself and the Chicago skyline in the mirror-like bean, I realized that I was staring at physics. I recognized that all of the images I was seeing were caused by light bouncing off of the bean and back to my eyes, reflection. The law of reflection states that the angle of incidence is equal to the angle of reflection. This was why depending on where I was standing around the bean (the sculpture is a combination of concave and convex mirrors, both spherical mirrors, as well as parabolic mirrors), sometimes I appeared shorter, taller, and even multiple times, like when I stand in front of fun house mirrors.
Here are some pics: