Crossbows are a very a cool weapon. They use tension and potential energy to shoot arrows. You first pull the string back, which requires a large amount of force, lock it in place with the spring system and then pull the trigger which drops the lock and sends the string and arrow launching forward at a high velocity. When the string is pulled back and locked in place, potential energy is built up. The more potential energy that is built up, the faster and stronger the arrow will launch once the trigger is pulled. Crossbows are fairly simple, yet very deadly.
This year in physics C I have learned many things. Many of which have expanded my knowledge in physics and as a person. I have learned much about myself. I now know that I wont be able to understand everything the first time, that I need to work hard to achieve the things that I want, and that Mr. Fullerton is for the boys. While I haven't been the best student this year, I can confidently say that Mr.Fullerton has taught me many skills that will stay with me for the rest of my life. From teaching me about mechanics to E&M and to how to study, I have learned a lot. Physics C has showed me that I really like physics and that it is with out a doubt the most astonishing thing ever.
Ever wanted to know the physics of curling??? NO???? Well to bad im gonna tell you. Curling stones are made from thick granite stones, weighting about 20 kg, with a handle on top. The heavy mass of the stones makes it so it doesn't slow down early. The sweeping of the ice before the stone reaches that spot decreases the friction of the stone with the ice. The little bit of friction caused by the front of the stone melts the ice a tad and creates water which reduces the friction. By controlling the friction between the ice and stone you can perform curling.
The harmonica is by far my favorite instrument, I love the different types of music that can be played on it as well as the many different characters you find playing it. Recently I have been teaching myself how to play a harmonica and have been wondering the physics behind it. In each hole of the harmonica there lies a reed, all of which are different in size. When you breathe into the harp of the harmonica the reeds vibrate at different frequencies causing the different pitches you hear. Each reed is fastened to the reedplate with one screw, allowing the rest of the reed to vibrate freely. The harmonica can be very simple and some of it can be very complex. Once you become proficient at the harmonica you can learn how to bend notes and master the harmonica.
Hey folks, breaking news, size doesn't matter. 100% of astrologists agree that a more massive planet doesn't necessarily have a larger gravitational force. Take Uranus for example, it very massive compared to us here on earth. In every way Uranus is larger than Earth, radius, mass, surface area, and volume. However because of earths smaller radius it has a larger gravitational force. The equation for gravitational force is F=G(M1M2/r2). The gravitational field on Uranus is 90% of that on earth. If you weigh 180 lbs on earth, ya gonna weigh 162 lbs on Uranus, pretty cool stuff.
The didgeridoo is an Australian instrument. It is made from eucalyptus tress hollowed out from termites. The didge is played by using a technique called circular breathing. Circular breathing is when you breathe into your nose and out of your mouth at the same time. It is much harder than expected but those able to master circular breathing can master the didge. The vibrations of the players lips and breath cause the air inside of the instrument to vibrate at different frequencies. When the frequency of the air matches the natural frequency of the air column it resonates. When the frequency's resonate it creates that big sound that you hear. The didges irregular shapes make its natural frequency very different from other wind instruments and make the didge quite unique.
The Discus is a moment in which the thrower does some spin stuff and then launches the disk across a long distance. The discus has many factors in which effect the throw of it. The first being momentum. During the spinning part, momentum is built up and then the disk is released. In the air the disk cuts through the air because of its aerodynamic shape. Also the spin is a very important part of its flight. The faster its spins, the more stable it becomes. It is very important for it to remain stable because the more stable it is, the longer flight time and more distance you achieve. With all these factors in mind, explosive release, and perfect from will result in a great discus throw.
Integral to the operation of the mechanical watch is the balance wheel. Balance wheels are constructed of a weighted wheel and a spiraled torsion hairspring. The wheel is composed of a metal alloy with low thermal expansion, and the spring is made of either steel or silicon. Energy stored in the watch's mainspring is translated through the gear train to the escapement, a trident shaped piece with a dedicated escapement wheel which delivers impulses to the balance wheel. The balance wheel is what allows a watch to run accurately, as the balance wheel functions as a harmonic oscillator due to the constant mass of the wheel and elasticity of the spring. Balance wheel oscillations are determined by the time taken to complete a semi-rotation, called a vibration. Balance wheel oscillations are usually within the range of 28,800 vph (vibrations per hour, or 4 Hz), which ticks 8 times per second. The period of oscillation T of a balance wheel (one oscillation, or two ticks) is determined by the equation, T=2π*√(I/k) where I is the moment of inertia of the balance wheel, and k is the spring constant of the torsional hairspring.
Writing physics blogs can be tough on the mind, soul, and body. It takes many minutes and many keystrokes to pump out a blog. It takes .045 Newtons per keystroke. Now add up all the keystrokes in this blog and you get a force of 12.87 Newtons. That's a lot of newtons!!!!! While this might not seem like a whole lot of force needed to type one of these blogs, imagine what its like when you slack off and have to write ten blogs in one day! Lots of force and lots of stupidity.
The Guillotine is a device used to cut off peoples heads. It was used very much ion the french revolution and hopefully isn't used at all today. While to guillotine is often seen as a machine of death, the mechanics and physics behind it is often underappreciated. The blade of the guillotine is brought up to the top of the device and tied down to hold it in place. When the object that is in need of some chopping is put into the restraints the rope holding the blade is cut and the blade, which is quite thick and heavy is dropped and proceeds to cut the object. The blade is at a 45 degree angle and is brought down on a track with the force from the blade itself. The angle allows for a precise cut and because it is at the angle, requires a lesser force, which makes it more stable. The mass of blade determines how fast and hard the blade falls. The blade has the force of gravity, mg down and the force of tension T up. When the rope is cut/let go of, it drops with the force mg and chops whatever lies below. While the guillotine is quite brutal is was very efficient and innovative for its time period.
Swings are found in children's playground and are very fun and enjoyable. They work just like a pendulum. A swing converts potential energy into kinetic energy as you swing. When you first get on the swing and take step back as far as you can to get the best swing you build up potential energy. When you pull your feet up and begin to swing your potential energy is converted into kinetic energy. When you reach the the maximum height form swinging your potential energy is built up and again is lost when you swing back down. By swinging higher you build more potential energy and swinging faster makes more kinetic energy. So remember that the next time you start swinging all's your doing is converting energy.
Almost everyone can whistle and people often do it when they are bored or are whistling along to a song, but how exactly do we whistle? Well, you can only make whistling sounds at the resonance frequencies of your mouth, because at the resonance frequencies the pressure changes due to the moving air. You can change the resonance frequencies by changing the position of your tongue. By moving your tongue up and down, and blowing harder or softer, you can change the pitch and amplitude of your whistle. So if you wish to become very good at whistling you better get that tongue moving.
Take way everything in the universe and be left with nothing. Well except there can never really be nothing. At the zero-point energy, or the ground state of the Universe, isn't actually a state of zero energy. On the contrary, it's a finite, positive value not only that but a universe of nothing still has a size, a shape and it is still a physical object. The concept of nothing is very hard for scientist to understand because there is truly never nothing. By having nothing you actually have something . If you were to take a vacuum and suck all the particles up and be left with nothing, you wouldn't be left with nothing. You'd be left with gravity. Gravity can never be truly taken away because space and time is really gravity. The universe is said to be made from nothing which makes everything you see nothing, and nothing every thing you see, think about that for a while.
Standing up can be hard sometimes and I personally prefer laying down, but you know life goes on and everyone needs to stand from time to time. So how exactly does standing up work? Say you are sitting down in your computer chair reading this blog post and you suddenly feel very thirsty and want to get up and get a glass of water. while you are sitting you have a net force of zero because your body is not in moving up or down, but as soon as you stand up a force is applied in the downward direction which pushes you up. As you stand up, your leg's have to produce a force greater than your force of gravity. The force of gravity on you is your weight x 9.8 m/s^2. By applying a force to the ground greater than the force of gravity you propel yourself upward until the legs are fully extended. Once your legs are fully extended and you are standing, your net force goes back to zero because the forces in the up and down direction are equal. Congrats you just learned how to stand up!!! Now go get your water and quench your thirst.
Everyone dribbles a basketball at some point of their life, but have you ever stopped and thought about the physics of dribbling one? When the ball is in contact with your hand it builds up potential energy. When you apply a force to the ball and begin dribbling it transfers the potential energy of the ball into kinetic energy. As the ball collides with the floor, the floor the pushes the ball back up to your hand. This is because of Newtons 3rd law: with every reaction there is an opposite and equal reaction. The faster and harder you push the ball the more kinetic energy it gets and the harder it bounces of the ground. While basketball isnt very easy for everyone the physics of it can be.
Besiege is a physics based game where players build medieval siege engines to destroy their foes. In the game you use things like springs, motors, wood blocks, and wheels to build almost anything you can imagine. Say you want to build a catapult to take down that castle in front of you, no problem. Before you begin launching projectiles out of the catapult, make sure it either has a counter weight or a suspension system to keep the catapult where it is. If you forgot to do this, the catapult will be carried by the momentum of the lever that is launching the projectile. The catapult will launch its self forward and destroy itself which is no good for you, But you can prevent this. By putting a counter weight you can weigh down the catapult just enough so that it stays where it is or if you want to be a little more fancy you can put a suspension system in. The springs will absorb the thrust from the projectile and distribute it throughout the catapult keeping it form flying away. While the physics of this game are not 100% accurate they are very close and can get you're brain really thinking.
Rainbow Six Siege is a popular first person shooter game that emphasis the use of destruction for tactical capabilities. With breakable walls, floors, windows and doors, destruction in the game is quite useful and very immersive. I remember a round in the map House where I was help up in the basement defending the hostage. I had reinforced the walls behind me with barriers that prevent the walls from being breached and put a c4 charge on the wall in front of me. I sat and waited to hear footsteps from the enemy. As the enemy broke down the barricaded door adjacent to the wall in front of me, I blew the c4 charge placed on the wall. The charge took the whole wall down and revealed my enemy. I then proceeded to eliminate the hostile and secure the win. Another notable mechanic in the game is the ability to shoot through walls and windows, as well as blow holes in the floor. To make the game balanced and more playable, the game does not allow for entire destruction. A c4 charge in real life would take an entire building down but in Rainbow Six Siege it can only manage to blow up wooden objects. While the destruction of the game is very cool and immersive, it has an even balance that defies physics but not by much.
During the recent inauguration of President Donald Trump, you can see bullet proof glass all around him. I got to wondering how exactly ballistic glass works. Bullet proof glass is made up of layers of glass and polycarbonate. The two materials are alternated and cannot not stop a bullet by themselves. A piece of glass by its self will shatter and a piece of polycarbonate by its self will be punctured. When the two are layered together, no bullet will get through. The bullet proof glass completely absorbs the impact from the round. Today's bullet proof glass can stop just about anything, from hand grenades to .50 cal rounds, nothing is getting through the glass.
Tom Brady is an elite NFL QB, some argue he is the best ever! With the up coming AFC champion ship game; Patriots vs. Steelers, I was wondering just how much force is need to put Toms little self into the dirt. Tom stands at a solid 6 feet 4 inches and a hefty 225 lbs. Now to calculate Toms force we use the equation F=ma. F is the force, m is the mass, and a is the acceleration. Knowing Tom, all he is going to do is sit in the pocket and not move giving him an acceleration of 0 as well as a force of zero. Well what does this mean??? It means even a baby could sack Mr. Brady!! But you better be careful!! Any force above 0 N will be a 15 yard unsportsmanlike like penalty, because Tom is a baby himself and will not stand for getting hit. Upon a hit of more than 0 N Brady will drop the deflated football and will begin to cry, this is normal and can be treated with a warm hug and kiss from Bill Belichick.
During the Steelers fantastic win last Sunday over the Chiefs, The Steelers kicker Chris Boswell set the NFL record for most field goals in a postseason game. Hyped up on the win and excitement I got to thinking, What is the physics of kicking a field goal? So I went and looked around and found exactly what I was looking for. Kicking a Field Goal is a very complex thing believe it or not. You have to consider things such as wind, air resistance, and momentum. Momentum is a key factor in having more force in your kick. With a higher momentum, the higher the force the kicker exerts on the ball. The kicker wants to kick the ball as hard and accurate as possible. Wind can either help or cause lots of trouble. It is very beneficial to kick with the wind because it can increase speed of the ball and accuracy. Kicking opposite the wind can slow your kick, or even blow the ball out of its path. Along with the wind and momentum their is a certain form you have to execute in order to kick well. The angle of the kickers body, pointed toe, arched back and the ball at a slight angle, all effect the distance and speed of the ball. The more angled the kicker's body is, the more momentum they will have, and therefore he will have more power. A field goal kick can win or loose a football game and it essential that NFL kickers are perfect.
Everyone seems to skip leg day, not me!!! Leg day is by far my favorite, especially back squats (I can back squat 365lbs ladies ). While the back squat is a simple movement, it requires tremendous power in your legs. To perform a back squat you must place the bar on the back of your shoulders, lower your hips down bellow parallel and bounce out of the bottom of the squat . Once you bounce you will reach a spot in the lift where you will have to push down on the ground in order to push yourself and the bar up. The back squat involves a lot of momentum and a very big impulse. The impulse occurs during the bounce at the bottom and without a large enough impulse you will fail the lift. Don't skip leg homies, leg day is the best day.
I'm a big fan of guns. I love shooting them and i love the eminence power they posses. Guns are really amazing machines, for being so little and simple they pack a punch. Mechanical reactions are what make guns guns. When shooting a handgun, once the trigger is pulled, the hammer falls down with tremendous speed and strikes the primer. The strike causes a spark which then ignites the gunpowder. The explosion form the gunpowder propels the bullet out of the gun at high speeds. It is quite incredible how something so little and compact can do something like this.
So you get in a fight and your gettin ready to throw a punch, you know you gotta hit hard and ya gotta hit fast, but do you know the physics of a punch???? The physics of a punch is actually much more complicated then one may think. The arm acts as a lever while ya fist and your body deliver the power. While it is quite obvious that you can find the force using F=Ma, there's much more to it. A good punch requires the whole body, not just ya arms. By rotating your hips and legs, you can pack a much bigger punch. The rotation generates more force and by delivering the punch and driving your hand threw the target, your punch will be much more powerful. If you ever find yourself in danger and need to throw a punch, make sure you throw your whole body into it, you don't want to be catching hands, you wanna be delivering them.
The hook grip is the best way to grip a barbell for the snatch and clean and jerk movements. To perform the hook grip, the lifter must first wrap their thumb around the bar, once they have their thumb in place, they then wrap their remaining fingers around the thumb and bar. This hook grip is much stronger than a regular grip. As the weight gets heavier, the hook will be your savior!!! The hook lessens tension in your forearms and makes it easier for you to perform the pulls and hip drives. The use of a death grip is no longer needed because of the hook grip. The grip may beat ya thumbs up a little bit and feel very uncomfortable, but with continued use of the hook grip, your hands will toughen and your PRs will soar!!!!
The snatch is a very complicated Olympic weightlifting movement. The movement is very difficult and often takes months of training to master it. To perform a snatch the lifter must squat down, grab the barbell with a wide grip using the hook grip. The hook grip is the best way to grip the bar. After the Lifter has gripped the bar, they then keep their head and chest held high while down in the squat position. When the lifter is ready they then pull the bar up along their body, once it reaches hip level, the lifter pops the bar off their hips with tremendous force sending the bar up past your head. Immediately after popping the bar of their hip the lifter drops below the bar into a squat position and catches the bar over head. Once the bar is caught and the lifter feels balanced, they must stand up with the bar over head, arms locked out, and knees straight. Once the lifter does this the lift is complete. The snatch requires a lot of power and explosiveness. The initial pull of the bar off the ground can be considered the most important part of the movement. If the pull is too fast, the bar will go to far over your head and you will more than likely loose balance and fail the lift. If the pull is not fast enough, the bar will not go high enough and the bar may very well fall on your head, OUCH!!!! Along with the bar speed, the speed at which you drop under the bar is very important. When you watch Olympic athletes snatch, you will see them snap under the bar with tremendous speed and bring the bar to a halt very quickly. The snatch is all about speed and explosiveness, with the proper technique and training anyone can become a master of the snatch.
The pages of APlusPhysics.com, Physics in Action podcasts, and other online media at this site are made available as a service to physics students, instructors, and others. Their use is encouraged and is free of charge. Teachers who wish to use materials either in a classroom demonstration format or as part of an interactive activity/lesson are granted permission (and encouraged) to do so. Linking to information on this site is allowed and encouraged, but content from APlusPhysics may not be made available elsewhere on the Internet without the author's written permission.
APlusPhysics.com, Silly Beagle Productions and Physics In Action materials are copyright protected and the author restricts their use to online usage through a live internet connection. Any downloading of files to other storage devices (hard drives, web servers, school servers, CDs, etc.) with the exception of Physics In Action podcast episodes is prohibited. The use of images, text and animations in other projects (including non-profit endeavors) is also prohibited. Requests for permission to use such material on other projects may be submitted in writing to firstname.lastname@example.org. Licensing of the content of APlusPhysics.com for other uses may be considered in the future.