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.