# jcstack6

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1. ## Is Gravity an Illusion?

From the earliest discoveries of gravity and when students first learn about gravity, they are told it's a force. The force of gravity is equal to mass times the acceleration due to gravity or Fg=(m1m2/r^2. That is just a fact. Or is it? Gravitational forces are actually much more interesting than just the relationship between one mass and another. Gravity is the act of changing space-time. Gravity causes space-time to curve into a bowl like shape pulling masses into the center of it. As a planet is a massive object, its core pulls the space-time surrounding it toward itself, pulling the atoms
2. ## High Notes on the Tuba

As an experienced tubist, I have been practicing bettering the quality of my higher range for years now, but it is still a challenge. The challenging aspect of playing clear high notes through a tuba can be attributed to physics. The higher the pitch, the higher the frequency of the sound waves. To increase the frequency of the sound waves, one must increase the speed of the air through the tuba. To do so, you increase the pressure of the air in the mouthpiece by pressing your lips close together to generate a fast stream of air. This seems simple enough, so what's the challenge. As frequency
3. ## Why is the sun hot?

I was recently reading a on a physics website (http://www.telegraph.co.uk/news/science/) an article revealing the actual reason why the sun is hot. Most people, like I, would think it is because of the energy dissipated from the collision of billions and billions of hydrogen and helium atoms. It seems like straight forward mechanics, the particles collide and dissipate a certain amount of heat energy due to the collision and the addition of the billions of collisions that happen every second makes the sun hot. In actuality, however, the sun is hot because of its immense weight. Its weight crea
4. ## Soun Board

Recently I participated in my high school's musical The Addams Family. Many times during rehearsal I would go to the soundboard to get mic'd and then have my mic checked. I never really knew what a soundcheck composed of, so I asked my friend Jack who worked the soundboard. In the simplest terms possible, one listens to the speaker/singer and they determine which frequencies sound good in the room and which sound awful. The ones that sound awful are cut out. I thought it was pretty interesting, but had no idea how certain frequencies could simply be cut out or stopped from being amplified by t
5. ## Fastball Physics

Dang that's a pretty insane fastball.
6. ## Time Travel

Many people think time travel is absolutely ludicrous, but one has to consider what kind of time travel they are referring to. To travel back in time is ludicrous, because if this were ever to become possible, there would have been discovered evidence of time travelers from the future that came to our time. Time travel according to Einstein's theory of Relativity, however, is not only plausible, but true. According to Einstein, as one increases the speed at which they travel, the rate of change of time is less for them than it is for an outside observer. Based on this idea, one can travel in t
7. ## Simpsons Physics 2: Springfield Gorge

I feel like all my dreams of jumping the grand canyon on a skateboard have been crushed.
8. ## the physics behind diving in the snow

It's all about the coefficient of friction man!
9. ## The Piano

Many people understand that the third pedal on a piano allows the notes to be held out for longer by not allowing the strings to be muffled inside, but the first and second pedals are a mystery. The first pedal is also a mystery to me so I won't discuss that one, but the second pedal makes the notes played softer. There is a fair amount of physics that goes into making this happen in a piano. To reduce the sound, the strings are lightly touched so that they cannot vibrate as vigorously, but not too much so that they are cut out. But why does reducing the amount a string vibrates reduce its vol
10. ## Walking the plank

In a show I recently stumbled upon, a man was told to walk the plank. This plank was nailed down, but considering a plank that wasn't nailed down, one could find the length at which to extend the plank off the ship so that it wouldn't tip over when a person with a known mass walked across it. To calculate this, one has to think about the torques applied to the plank. The torques applied, assuming the person is at the end of the plank and the plank has a uniform mass, is only the torque applied by the person and the plank. The torque provded by the person is calculated by the person's mass mult
11. ## Bowling

When looking at the sport of bowling, one can easily say the velocity at which the ball is thrown and its mass are the factors in whether or not the pins fall down, but which one matters more, or do they have the same amount of importance? When looking at this question, momentum has to be focused on. The momentum of the ball as it is thrown is what causes the pins to fall down. As momentum is conserved as each pin hits another, the initial momentum of the ball is what matters most. But what is momentum? Momentum is defined by an objects mass multiplied by its velocity. Therefore, the balls mas
12. ## Ice Skating

When a skater goes into a spin, they usually start it with their arms out wide, spinning at a slow pace. Then the skater pulls their arms in and the speed at which their rotating increases and finally as the spin comes to an end, their arms extend again and they slow down. Many people understand that physics is incorporated in skating, but they don't understand how much goes into a simple spin in terms of physics. Rotational momentum is defined by the objects moment of inertia multiplied by their angular velocity. An object's moment of inertia is defined by their mass multiplied by their radiu
13. ## Sleding

Many people spend the winter practicing thrilling winter sports such as skiing or snowboarding, but I like to stick with simplicity. Sleding requires very limited skill to still have the thrill of gliding down a hill. There is also a lot of physics behind sleding, specifically how to turn on a sled. People seem to automatically know that they should lean to a side to turn to that side on a sled, but why? It's all about the normal force. The sled glides down the hill because of the force of gravity on the sled and the person in the sled but turning is a different story. Once a person leans to t
14. ## The Final Day of Blogmas

Blogmas is my favorite holiday.
15. ## Roller Coaster

That's so cool to think about that energy can't be lost or created even in the scenario of a massive rollercoaster.
16. ## 8-Ball Pool

Thanks for discussing conservation of angular momentum between the balls as they role, great job.
17. ## Returning a serve

In my limited time playing tennis for school and ping pong in my free time, I've learned how to properly return a fast serve. I would always see a quick serve coming at me and be tempted to swing hard back at it, but that would always end in the ball soaring off to either side. My coach instead told me to just hold my racket still and steady and let the ball bounce off of it. This technique has a lot of physics behind it that makes sense. Think of a ball being bounced on the floor. The floor does not swing at the ball to propel it back to your hand, rather the ball merely hits the still floor

I often play pickup basketball with my brothers, the teams usually split up as me and Paul vs Nathan and Dave. Paul is garbage, however his terrible form and his "signature move" has a lot of physics involved with it. Paul believes the greatest shot is one where he dribbles along the three point arc and chucks up a shot one handed while falling backward. He believes the best way to make this shot is by aiming for the white square on the backboard. This is surprisingly not the best tactic however. Even though every coach tells their 5 year old players to aim for the magic white box, in Paul cas
19. ## Biking

Biking is one of the most electrifying activities out there. Picking up speed as you approach a jump, wondering how much air you'll get and then being launched into the air. Not many people, however, know all of the physics behind just simply going off a jump. It can be thought of in terms of kinematics by knowing the bikers initial velocity, but then one neglects how the biker obtained that initial velocity. Rather we can consider work and energy to talk about the correlation between the force of the bike, the distance the biker accelerates, their final velocity and the height they get off of
20. ## Rotational motion (don't forget friction)

In a recent lab done in my physics c class, my group was experimentally determining the moment of inertia of six different objects. We set up a ramp for the objects to roll down at an angle of 3.325 degrees. We rolled the objects down the ramp, recorded the time for each object and then found each objects linear acceleration, radius, angular acceleration, mass, net torque and finally moment of inertia. When we checked our answers with our teacher they were horribly wrong, like an average of 200% error. This was because we neglected ed to include for unction in our calculations for torque.
21. ## Cereal

You may have wondered why it seems that all of your cereal clumps together in the middle of the bowl, even when you only have a few bits left to eat. The fact that cereal accumulates toward the center is due to something scientists have called "The Cheerios Effect." In 2005, the effect was mathematically proven. The surface tension between the milk and the bowl causes the milks surface to cave in slightly toward the middle of the bowl. Similar to the cohesive and adhesive properties of water, these properties in milk cause a concave surface of the milk. Clearly once one understands that the su
22. ## The Deathroll

I guess sailing can be cool
23. ## Laser Surgery

That is fascinating that a specific part of your skin can be targeted by using a specific wavelength!