Radio

Physics continues to play a part in everyday life, even while listening to the radio. Transmitters send radio waves at a specific frequency so that our radios can transfer them into sound. This allows the broadcast of many different channels. Listening to the radio also made me think about the differences between the voices of Perry and Price. What makes their voices unique to themselves? The sound waves that are emitted by their voice box contain different frequencies and harmonies. The graph of this sound wave would not be a definite sine function, but a graph of many crests and troughs.
The Mighty Mo contains many radio transmitters so that it can communicate with all military command.

Speed bump

I was driving in my car when I approached a speed bump. I slowed down and as the car's front two wheels fell, I could feel the frequency of the springs. This meant that physics was at work yet again. As I landed, the car bounced, as if it were in harmonic motion. The weight of the car landing created the force that would make the car no longer exist in equilibrium. This motion, however is not in simple harmonic motion. As shown in this picture, the car's shocks will actually compress a little as it rides up the bump in order to keep the body of the car at a constant level.
Upon landing, the shocks will become stiffer (higher spring constant) so that the car will not bounce. The spring constant of shocks are able to change because of hydraulics and air pressure.

hercules hold

This weekend I had the chance to participate in the world's stongman competition, by watching it on tv. In the event called the hercules hold, contestants need to hold up two pillars with pure strength. They need to exert a tension that provides a torque to balance out the weight of the pillar due to gravity. The height of the center of gravity multiplied by cos(o) multiplied by the weight of the pillar should be equal to tension * sin(s) * height of the chain * sin(o). Therefore the stongest man does not always win this competition. The one whose body fits the event the best will win. A man with a shorter horizontal span will decrease the ammount of tension required and the man who is tall enough to hold the chains parallel to the ground will maximize the tension value.

pool

This weekend I went swimming in a pool. I jumped in and with no surprise, I felt much lighter. This was due to the buoyant force. The volume of the displacement of pool water multiplied by the density of pool water and gravitational force was equal to the buoyant force. My weight minus the buoyant force was equal to my weight in the pool.
If I floated instead of sunk in the pool, then the buoyant force would be equal to my weight.

spoon levers

I was eating ice cream when I noticed that using a spoon required physics. The a scoop of frozen ice cream needed to be pried with force from a spoon. By using the side of the bowl as a fulcrum, I applied a downward force with my hand. Once there was enough force to overcome the static friction force of frozen ice cream, the small scoop was lifted. If I moved the handle of the spoon farther away from the fulcrum, it would have made lifting the ice cream easier since less force is necessary because the distance between the fulcrum and my hand increases and the distance between the fulcrum and the ice cream decreases. If the handle of the spoon is closer to the fulcrum it will be harder to lift the ice cream.

Dizzy

So I was sitting on my chair in front of the computer not knowing what to write about for this weeks journal entry. I began to spin in the rolling chair and I realized that that was actually physics. I stuck both of my feet out parrallel to the ground and although it was moving at the same angular velocity, their tangential velocity was more because the radius from my toe to the center of the chair was larger. I began to spin faster and faster. My toes now had a higher tangential acceleration but the same angular acceleration. I began to count in radians the number of spins that I could do. 2 pi, 4 pi, 6 pi, 8 pi, 10 pi, 12 pi . . .



no that is not fire. This is turning into a biology blog.

Jumping in Sand

Why is it harder to jump higher in sand than it is to jump on a court? This is the question I began to ponder as I grew exausted from playing beach volleyball. I then realized that Newton's Laws were the reason for my exaustion. In order to jump, the legs need to exert a force on the ground so that the ground exerts and equal and opposite force to push the body in to the air. In the gym, nearly all of the force exerted by the floor is transfered to the jump. On the beach however, tiny sand particles cushion the force of the jump by spreading outward. Therefore not a lot of the force is transfered to the jump because some force is needed to push the sand particles outward. The static friction of the sand is also relatively small compared to the solid, one-pieced court.

Halloween Humpty Dumpty

With Halloween coming up, unopened candy litters my house and so to tidy up the mess, I eat the candy. I ate some hershey's chocolate first and then some skittles. Finally I tried the M and M's and physics kicked in. When I was opening the bag of M and M's, all of the different colors fell to the floor. The impact caused many of the hard candy shell to break, sending small pieces in all different directions. The conservation of momentum tells me that the momentum of each M and M is the same as the momentum of the pieces that it broke into. The mass of the M and M multiplied by the velocity right before impact is equal to the sum of each shard's mass multiplied by its own velocity right after breaking.
Humpty Dumpty?

NASCAR

Over the weekend there were many intriguing football games to watch from high school, to college, to professional. There was even couple of baseball games that decided who would advance to the world series. What caught my eye, however, was what is often overlooked on Sunday mornings. Nascar aired for two and a half hours ( I didn't watch all of it, of course). While I was becoming dizzy because of the cars looping around in circles, I began to realize the physics that allowed the cars to move at such high velocities. Even if the cancellation of NASCAR would solve the problems with gas prices, I began to understand the thrill of the sport. All was going well until I saw in bright colors what friction looked like. Even though I know the fire wasn't fully caused because of only friction (like how cavemen started fires), friction against the wall as well as the force that it pushed back on the car with equal and opposite force made Terry Cook run from his burning truck. His high horsepowered engine allowed him to do maximum work in a little time. His truck could accelerate up to the highest velocities, which was good and bad in this case.

Da Ref

So I was at a volleyball game this week, cheering my heart out and forgetting about school when I remembered all about physics. The ball began bouncing back and forth with different kinetic energies, but that was not what I was interested in. The top referee stood above all in the gym and had a higher potential energy than if he was at any height lower. His mass multiplied by gravity and the height of the stand (about six feet) would represent his total potential energy. If he were to fall off of the stand (I wished), at the instant before he touches the ground, his kinetic energy would be equal to that of his potential energy (if there was no air resistance). While in mid air, his potential energy added to his kinectic energy would have been equal to his initial potential energy. Who knew that Newton's law of the conservation of energy exsisted in volleyball?

School bag

So I was about to miss my ride to school at 6:30 in the morning. My mind was still half asleep when I picked up my backpack from the table and placed it in the trunk. I then had a realization that I had done work! Or had I. Considering the table was at the same height as the trunk and I had carried my bag at the same velocity, I accomplished no work. I picked up the bag from the table vertically, so no horizontal force was accounted for. Now it was time for the real kind of work. I would have to spend another eight hours of my life studying and learning.

Kayaking

This weekend I had a kayaking race on the Ala Wai Canal. As the race dragged on, I grew tired. I wondered why it seemed so hard to reach the finish line, and then I remembered physics class. The force I was putting in to paddle forward was being countered by the kinetic friction of the water. My kayak would not glide through the water. In the last 100 meters of the race, my boat began taking on water. The mass of my kayak went up, increasing the normal force as well as the kinetic friction that required more force to move the boat at the same acceleration. I also learned that friction from a liquid is different from that of a solid. At a higher velocity in liquid, friction actually increases, compared to friction of a solid where kinetic friction is constant. Luckily for me, the shape of my kayak was streamlined so that less energy was required to push water out of the path of my boat.

Here's a basic diagram showing the forces on my boat. Buoyancy and normal force equals that of weight since my boat did not move in the y coordinate.

Basketball

The other day when I was shooting baskets, I had a new realization for the physics behind it. I would have to shoot the ball at a specific angle and velocity to make the ball land in the hoop. With my release point at 6' 8", the delta y value would have to be 3' 4" while the delta x value would be the horizontal distance to the hoop. Gravity also pulled the ball down at -9.8 m/s2, affecting the time that the ball was in the air. Thank goodness I did not have to literally calculate the exact angle and velocity each time I shot since the body gains a feel for it. I would also have to factor in the equal and opposite force of the ball bouncing off of the backboard on a bank shot.

Here's a game that simulates shooting a basketball with angles, gravity, velocity, and equal and opposite forces.

H.O.R.S.E.
Test your trick shot skills in a freestyle game of basketball Horse.

I'm not in Heaven, but it ain't Hell

Before I knew it, my baseball coach became my AP Physics teacher. Without sugar-coating the difficulty of the course, Doc emphasized the work that would need to be done. Although a little tough now, I know the insane scenarios that he explained to us on the first day are soon to come. Homework is not as much as expected since the concepts of some nights' homework are more easily grasped than others. As the year goes along, I am looking forward to learning about Physics in the lab by discovering in order to understand. I am willing to challenge myself in a hopefully uphill year.





Grading policies have been very fair so far. Tests and quizzes, however, seem to sometimes be do or die since the answer to one problem is used in the next problem and so forth. I have been lucky enough to "do" so far, but whose to say that I won't "die?"





The truth about Physics is that it is more difficult because of the time needed for other subjects. So here is my quick thought for Physics and school as a whole. Summer is long gone.