Torques - Turn on the Light!

Once we learned about torques, I came home and realized that there are torques everywhere in all sorts of everyday tasks. Things as simple as opening a door or even turning on a light. I actually thought of physics first when I opened the door, but since we used that example in class I decided to use the second torque I thought of and that was turning on the light.

In my house, the light switches are the regular flip-switches and I realized that, as small as it is, a torque is what makes it turn. The rotation point is inside the wall behind the plate, the lever arm is the protruding switch, and the force is provided by the finger that is flipping the switch.

Another regular task that reminded me of torques is, interestingly, flushing the toilet. The handle is the lever arm and the rotation point is the part that connects to the toilet. Again, you provide the force.

In fact, all the mechanical levers I can think of involve torques to operate. Can a person's limbs and joints also involve torques? Like the knee or elbow? I think it's amazing how many instances I can think of where torques were applied.

Boom Blox - Physics in Wii

My sister recently bought a new game called Boom Blox for the Wii. What I found most interesting about this game is the amount of physics involved in playing it.
The main goal of the game seemed to be to knock down all the blue cubes (or gems) through various creative means using as few throws as possible.
In addition, the Wii remote even allows the game to calculate how successful to make your throw based on how much force you put into it. It is not just enough to do the throwing motion, you actually have to put some muscle behind it to get a "Strong Throw". Otherwise you'll get a "Weak Throw" and the heavy blocks won't move very much.

I took a picture of my sister playing Boom Blox:

Specifically, there was one game called Teeter-Totter which required you to knock a heavy block onto the balance beam to tilt it and make all the gems fall.

Here are the before (the initial setup) and after (with the blocks falling) shots.

Overall, I was intrigued at how a very simple game of physics could be so much fun to play and yet I was hooked the first time I tried it. Without even really thinking about it, I was applying my knowledge of physics concepts like weight, force, projectile motion, velocity, etc. to help me win the game.

Cirque Du Soleil - Trapeze

On Saturday, I went with my family to see the Cirque Du Soleil show Saltimbanco. It was definitely worth it. It was humorous, the acts were amazing, and (of course) it had tons of good physics! Unfortunately, the show doesn't allow for any photography so the picture I posted is scanned from the official program book they were selling.

This was only one of the many amazing stunts they performed. If you look closely, (click on the picture for the full sized image) you'll see that the second girl is being held up only by the first girl's flexed foot! I thought this was incredible, especially when you consider how much downward force/weight her foot is supporting. In addition, the first girl isn't sitting firmly on the trapeze but holding on with one hand and her leg!

Another amazing stunt was when one man climbed up a pole using only his hands. He climbed straight up with only his hands touching the pole while keeping his body pretty much parallel to the pole. It's unbelievable to think how much strength that must require.

Overall, I was very impressed by the show and I think most people would enjoy it. If you've never seen a Cirque Du Soleil show, you should definitely consider attending one in the future. It was a wonderful mix of stunts, humor, and story and I would most certainly go again if I could.

Course Reflections

So far, I have been pleasantly surprised at how much I actually enjoy this course. Normally, I don't like science. But this year I am actually finding Physics to be a very fun class. Of course, I am worried that the material will get harder later in the year. But I have no doubts that class will still be fun.

My goals for this class, especially after having such a hard time in Chemistry last year, are to enjoy the experience, understand the concepts, and earn at least a final A- grade. Although, right now, I'm feeling that as long as I'm enjoying myself, I shouldn't be stressing too much over my grade.

I feel that, so far, I have been fairly consistent in my effort and performance on labs, quizzes, and homeworks. I think I should work at being more consistent on tests but, overall, I am ok with what I have done so far.

As for my "state of mind" about this course, I have, as you can see, chosen a balloon as my image. This is because I feel that while I am hovering around the same place grade-wise, sometimes I am confused at the beginning and my head is "full" of air rather than information. However, by the middle of the section I usually have begun to understand. At the same time, I chose a balloon to represent how much fun I am having in this class.

Overall, I am having a great time in this class and I hope the rest of the year will be just as enjoyable.

Newton's Laws in Action

On Saturday, we were at my sister's gymnastics class and I noticed a beginner's class jumping over small, padded blocks. As the kids jumped one by one, I realized that this was Newton's laws in action.
In order for the kid to jump over the block, he had to be able to exert enough upward force to counter the downward pull of gravity. By doing this he would be changing his net force. Initially, before he jumped, the boy would have a net force of zero and he was at equilibrium. At this point, the free body diagram would have two equal forces, the downward force of weight and the upward normal force.
However, in the instant that he jumped, by pushing off from the ground, the boy had increased the upward force and therefore caused his body to rise off the ground. In this instant his net force is no longer zero because the greater upward force means the two forces no longer cancel out.

Ice Water

Today my whole family went down to my grandma's house for dinner. We had lots of delicious food like steak, noodles, and stew. While eating dinner, I had drank all my water and went to get a refill. While adding ice to my cup of water, I noticed that the water level was rising with each ice cube I added to my cup. Then I realized it was like the displacement we had learned about in Physics. The ice caused the water to change position positively. It was water displacement! Adding ice caused a positive displacement, while removing ice caused a negative displacement.

In addition, I noticed that by dropping the ice cubes into my cup, the cubes were falling from 0 m/s with a -9.8 m/s/s acceleration. However, because each added cube raised the water level, the distance each subsequent cube had to fall became shorter than the previous cube. As a result, the last cube I added fell a shorter distance in less time with a smaller final velocity than the first cube I added.

Spin the Wheel

Earlier today, while I was running one of the games at the Aiea Country Fair, I realized that all of the games applied physics concepts like displacement, velocity, and acceleration. The game that I was running was the "Spin the Wheel" game. As children stepped up to spin, I noticed how some would spin it clockwise and others, counterclockwise. Some spun it really fast and other put less force in their spins.
In one instance, a boy spun the wheel really fast. As I was watching to see what number it landed on, I noticed that, with each rotation, the displacement returned to zero before increasing until the rotation completed again. In addition, I also noticed how the slowing wheel was exhibiting negative acceleration until it finally came to a stop, or a velocity of 0 m/s.
It was also interesting to observe how occasionally the wind would spin the wheel in the opposite direction after it had stopped, often resulting in better numbers for the players. Overall, it was a fun day at the fair and I got to observe physics principles while there.