ncharles

As all Rochesterians know, winter driving is not easy and can get out of hand very easily. But why? Well it is rather simple. The added snow and ice on the road causes the coefficient of friction between the tires and the road to be much much smaller. Using the equation Ff=uFn with Ff being the force of friction, u being the coefficient of friction and Fn being the normal force we can see that when the coefficient of friction decrease (while the normal force is kept constant) the force due to firkin decreases. This causes the tires to slip a lot easier on the snow and ice than it would in just dry pavement. Similar to driving on snow/ice is driving on water. Although not a sever, when the road is wet the coefficient of friction between the tires and the parent is less than dry parent but not as less as snowy or icy pavement. So when you go driving this week be extra careful and be ready for a spin out.

As i watch the Denver Broncos play the New England Patriots in the semi-finals of the road to the Super Bowl, I have realized at how important the position of the quarterback is. Inorder to be successful, the quarterback must have keen senses and know the basics of physics. When looking deep to an open receiver, the quarterback is able to subconsciously analye three main components to the throw...the angle, speed and timing (a classic example of projectile motion). The quarterback must know exactly what angle to throw the ball at in order to loft it perfectly into the path of the wide receiver. A fluctuation of a mere 5 degrees could be the difference between a touchdown and a turnover. Second is the speed. The quarterback must be able to throw the ball with enough speed to get it to the hand of the receiver without throwing it too far and over throwing the receiver. Also, if they speed it to small, the defense will easily intercept the ball and possibly score. Finally, arguably the most important aspect of throwing a deep ball is timing. If the quarterback throws the ball a second or two too early or too late, it will miss the target receiver and result in an incomplete pass.

Have you ever had to walk through feel of snow and your feet just fall right through it? Well this has happened to me more times than i can count. Although i do not own a pair, the great invention of snow shoes were intact created to solve this simple problem. The problem without snow shoes is that your weight is distributed on such a small area that the snow cannot hold you up and you can easily comports the snow. The purpose of snow shoes is to increase the area that your weight is being distributed on. This increase is weight distributions cases less force to be applied on each snowflake which would make it compress much less.

In the history of the world, there have been millions of bombs dropped by any nation during a war. However, what most people never think about is the physics behind dropping a bomb. The bombardier must take into consideration the speed at which they are flying, the horizontal distance away from their target and the height at which they are flying. Say, for example, the average B-42 bomber has a cruise altitude of 39,00 ft (12,000 m) and a cruise speed of 545 mph (926 kph). If a bomb were to be dropped with these conditions, the bomb would travel a horizontal distance of 12.72 km in its fretful in 49.5 seconds (ignoring air resistance). If the bomb team was given a target to hit with a radius of 1 km, then mistiming the drop my a mere 5 seconds could cause the bomb to miss by 300 m. This could mean the difference between winning or losing an entire war...some pretty big stakes. Luckily now there are bombing systems that are very accurate and a bomb team is no longer required; but back in the day, this was a stressful task that took much focus and careful calculations.

Nope just a term!

Many people may be familiar with FIFA (Fédération Internationale de Football) and possibly the FIFA video game put out by EA Sports also. To the average person, the video game FIFA may seem dumb or boring, however, as an avid FIFA player myself, i experience a very exciting roller coaster of emotions when i play. There are many techniques to play FIFA that will all lead to success; but the technique that is the most effective and efficient is called "Sweat". The goal (pun completely intended) of this technique is to cross the ball from the sideline and head it in to score a goal, however it is more complex than that. First off, the user must find a suitable player to run down the sideline with. The only attribute that this player must possess is pace. There are two components pf pace: acceleration and speed. The acceleration, as we all know, is the rate at which an object gains speed. If the player of choice has a greater acceleration than the opponents player, your player will be able to cover the same amount of ground in a shorter time which will allow your player to create a gap between him and the opponent. Speed is also very important in order to maintain the gap created and not be easily caught by the opponent; these two attributes combined prepare for the second step: the cross. There is a lot that goes into the perfect cross. First the player must rotate their hips with a very high angular speed in order to send the ball in the correct direction. Second, the player must kick the ball with the right force and at the right angle to place it just in-front of the player that is aiming to head the ball to score a goal. Finally, arguably the most important step to the process of "Sweat" is the header. The model header is 6'3" or greater in hight and VERY strong. This makes it easy for them to head the ball because they do not need to jump as high to reach the ball at the maximum height possible. Also, the player heading the ball must mentally time the header in order to redirect the ball a full 90 degrees to get it on target. This requires a very fast turn of the head, similar the the rotation of the hips on the cross, with a very high angular speed. After the header happens, the goalie will have no time to react and the the ball will go in the goal without a doubt.

Have you ever looked out of the window on a windy day and noticed that only the tops of the trees are shaking? The answer is most likely yes but you probably haven't thought of why this happens. The wind in general applies a force on the tree witch is what causes the tree to move, however, the tree can withstand some force and keep sturdy. As the force of the wind is applied further and further up the tree, the torque in being increased because the length of the "lever arm" is being increased. The maximum torque at the very top of the tree passes the threshold force that the tree can withstand and causes motion at the top of the tree!

Schlieren Imaging is an optical technique which allows viewers to see physical changes in air which the human eye cannot detect. Like many other imaging techniques, Schlieren Imaging involves a few basic principles such as refraction (how light acts/bends as it changes medium), reflection (the act of light bouncing off of a reflective object such as a mirror), refractive index (the amount light bends as it passes into a certain material) and density (which affects refractive index). A Schlieren Imaging System allows one to see the different densities that light rays from a source pass through: even if not visible to the human eye. One of the most common ways of setting up a Schlieren Imaging System is the “z-style” (as shown in the attached diagram). This includes a single concave mirror, a light source, a knife edge or color filter, and a camera. As shown in the diagram, the light shines onto the mirror, which reflects and focuses the light to a single point onto the knife edge. The knife edge is used to block out light bent at a specific angle due to a density change in its path. This blocking of light creates a dark spot in the image or field of view which gives the image contrast and clarity, alowing you to be able to see the pocket of air of different density.

Sports have been a large topic of focus in this here blog and i will continue that trend with a new application of physics...BASKETBALL. Now many people may think that basketball is a simple game of putting a ball in a hoop but it is much more complicated. Im only going to focus on the free throw in this post. The first part of the free throw is lining up your shot. This takes practice in order to learn the typical trajectory of your shot so that you now what angle to shoot it with, the amount of force to apply to it and the night to shoot it from. Right after the shot comes the follow through. The main part of the follow through is to apply backspin to the ball. This makes the shot more likely to go in because rather than bouncing normally, the backspin decreases the angle of "reflection" (for lack of a better term) of the ball and keeps it closer to the hoop so it can roll in.

Have you ever experienced your ears popping before? Why does this happen? Well, you ear has a small pocket of air in it that, usually, has the same pressure as the outside air. However, when you are on the takeoff or decent of a plane ride the atmospheric pressure of the air around you is constantly changing at a fairly fast rate. Inside your ear there is a small tube which is made for equalizing the pressure of the air in your ear and the air outside your ear. This opens when you swallow and often when it is opened you hear a pop; and that is the pop you hear. The bigger the difference in pressure the bigger the pop. So next time this happens to you, don't be scared...its completely normal!

As you may have figured out already, I tend to enjoy writing these blogs about sports and fairly dangerous activities...so I will continue this trend with curling. Although not the most exciting sport to watch, playing it is a whole different story due to two main physics principals: friction and collisions. Curling is played on a ice surface to allow the stone to glide easily and smoothly to the target because the friction between the ice and the stone is very little. If you've ever seen even one throw of a curling game then you have seen the people so stand there with brooms and brush the ice and you probably thought "well that just looks silly" (myself included). Well there actually is a purpose to this; the act of brushing the ice causes the top layer of the ice to met and turn in to water. The friction between the stone and water is much greater than the friction between the stone and ice. So, what these people are doing is slowing down the stone in order to make it stop right in the middle of the target circle. Similar to billiards, curling is filled with collisions; and that is the biggest part of the game. The ability for the thrower and the 'brushers" to judge the speed and direction necessary to accomplish a task is key to the sport. For example, is the thrower throws the stone way to fast, the brusher wont be able to stop it and then is will smack into every other stone and they will all be scattered in every which way. This obviously isn't what is wanted because the task of stopping in the middle was not achieved. Rather, the thrower wants to throw it at just the right speed in order for the stone to collide with one or more stones and stop right in the middle while sending the other stone out of the target area. So, next time you watch or play curling, you will actually know what the goofy people with the brushes are for!

On thing that i would love to do in my life time is go skydiving. Fro what i understand there are three main parts to a skydive: free-fall, decent by parachute and touchdown. During free-fall, you re acceleration toward the earth at a rate of 9.81 meters per second per second. This just means that every second, you increase your velocity by 9.81 meters per second. However, due to air resistance, there is a maximum velocity that you reach because once you reach that velocity the drag force is equal to the force of gravity with causes a balance of force and therefor no acceleration. Second is the decent by parachute. When you first open your parachute, you slow way down because air resistance is greatly increased due to the parachute...which is its job. When the parachute is out, the rage force is equal to the force of gravity with allows you to fall at a constant speed. Then finally, touchdown. When landing back put earth, it would be smart to tuck and roll rather than just land. The reason for this is that if you do this you act sort of like a spring and don't take all the force at once but take it little by little. This will prevent injury and make your skydiving experience a lot more fun.

A common activity that nearly any person ever could participate in is bowling. Whether you're a 35 year old professional, scoring 300 like its nothing or a 5 year old beginner using the bumpers, there still is one thing that always stays the same...physics. First of all, if you've ever stepped over the line while bowling, chances are you slipped and fell...why? The lane of the alley must have nearly no friction in order for the ball to maintain its initial speed, and to allow for better control of the ball and the application of spin. That brings us into spin. When a player apply spin to a ball the rotational inertia causes the direction of the ball to be altered based on the direction and amount of spin. Professionals look to make the ball travel in a near parabolic path in order to maximize the chance of getting a strike.

Billiards (aka pool) is a common sport in which the competitors try to knock their balls (either stripes or solids) into cups around the outside of the table. They use a Pool Cue to hit the Cue ball into other balls which will cause them to move in certain directions and ultimately into the cup. This sport is different than others because it SCREAMS physics: collisions, angels of incidence and reflection, friction and many other concepts are what this sport revolves around. First off, when the cue ball collides with other balls (assuming perfectly elastic collisions) momentum is conserved. This comes into play when the competitor is judging the amount of speed necessary to complete a shot. The more speed the cue ball has at impact will mean that the speed of the ball it hits will also increase. Another shot to perfect in billiards with the bounce shot. More often than not, the balls are not perfectly lined up to get the best shot possible.....so, the competitor needs to utilize the walls and bounce the ball off the wall in order to hit the target ball. When judging the angle to bounce the ball at, the competition must know that what ever angle the ball hits the wall with is the same angle it will bounce off with (angle of incidence=angle of reflection). Finally, frictions plays a very important role in the collision of the cue stick and the cue ball. Professional pool players put spin on the cue ball in order to make it do different things to give them an advantage. Often, the player will put chalk of the end of the pool cue to increase the friction between the sick and the ball which will increase the amount of spin on the ball and with more spin comes better results. So next time you play pool, think of the physics behind it.

Nearly every person in the world will, at one point in their life, use a pen to record, solve of draw something on paper. However, no one stops to think how and why this luxury occurs. How does ink come out of the pen when writing but not while just sitting there? A few main factors determine the flow rate of the ink: the pulling power of the pores of the paper, the pulling power of the pen and the surface tension of the ink. The pores of the paper act like little mini hands that grab on to the surface of the ink at the tip of the pen; rougher paper will pull out ink more quickly, while smooth surfaces struggle to pull out ink. Then, due to the surface tension of the ink, as some of the ink is pulled out, more comes with it. When the pen is not writing, there is nothing to pull the ink out so no ink flows out of the tip of the pen. Also, when the pen is moving, another factor that contributes to ink flow is the speed of the pen: when its moving faster, ink flows out at a faster rate. Now, when ever you write something, you will think about how you are actually making words.

Here in the North East, skiing and snowboarding is popular activity that many people participate in. However, most people don't think about the gobs of physics behind gliding or falling down the hill. For the more skilled skiers and snowboarders, the experience of tumbling down the slope is not very present in their time on the mountain. So, the main physics behind their ride is friction and gravity. Obviously, gravity allows them to move and accelerate down the mountain. However, what many people don't think about is friction. Although very small, the friction between the bottom of the board and the snow actually plays a large roll in the speed of the person. The main factor to decreasing the friction is coating the bottom of the board in wax. This makes the board ever smoother and decreases the coefficient of friction between the snow. Without this, the board has a tendency to reach a maximum velocity and not speed up after that, which for people who want to go very fast, is not appealing. So next time you go hit the slopes, make sure you wax you skis or board to go as fast as possible.

The newest thing these days in the world of sports is artificial grass--or turf. Many professional teams, and even high schools like our own, are installing turf in order to reduce the maitnence required to maintain a sports field. There are two main differences between grass and turf: bounce and friction. First id bounce; Compared to grass, turf has a higher coefficient of restitution which means that, off the bounce, the ball will retain more of its speed ultimately speeding up the game as a whole. This will force players to have better reactions in order to judge the ball at a faster speed. Also, the friction between the ball and turf is less than the friction between the ball and grass. This, also, dramatically increases the speed of play because the ball moves faster as a whole. Players would need to more accurately weigh their passes in order to achieve success as they do on grass. Ultimately, turf increase the speed of play which is part of the reason it is making a revolution in the soccer world.

Name: Everybody Brought Mass to the Party! Category: Dynamics Date Added: 2015-09-28 Submitter: ncharles Published on Sep 25, 2015Find out when mass cancels out from an equation, which it often will in physics problems. Want Lecture Notes? http://www.flippingphysics.com/mass-p... This is an AP Physics 1 topic. Content Times: 0:05 1st example 1:17 2nd example 1:49 3rd example 2:25 4th example Multilingual? Please help translate Flipping Physics videos! http://www.flippingphysics.com/transl... Previous Video: Does the Book Move? An Introductory Friction Problem http://www.flippingphysics.com/fricti... 1¢/minute: http://www.flippingphysics.com/give.html Everybody Brought Mass to the Party!

At any amusement park, there is always at least one roller coaster; its make makes the park. However when people ride it they don't actually think about how it works and the physics behind it. First of all, the first hill is the biggest in order to accumulate enough energy to get through the whole thing. And after that, gravity and the conversation of energy take the lead. Although present, the friction between the cart and the track is very little and doesn't change much. Because of this, at any point on the ride, the sum of the potential energy and kinetic energy is equal; whether going up, down or even around a loop. So the next time you ride a roller coaster think about how its all gravity after the first hill!

I can't wait to see what things you discuss in your next blog!!

As you can guess, this is my first blog for the AP Physics C year (one of about 40). In my free time I dabble in the sports of soccer, basketball and tennis and although I am not the best or star player in any of the sports, I would consider my self consistent and fairly talented in them all. During the scarce moments in my life during which I am not playing sports, I am either doing homework, playing FIFA on Xbox, or sitting on my phone using Snapchat, Twitter and/or Instagram. I have four siblings (one brother and 3 step-sisters) of which I am the second youngest (I am also the youngest kid in my grade). My two older step-sisters are a sophomore and freshman in college and my brother is a freshman in college also; my younger step-sister is in 5th grade at Iroquois. Throughout my academic career i have gotten good grades and I will do everything in my power to keep it that way for senior year. I enrolled in the AP Physics C class, because I did well and loved last years Physics with Mr. Powlin. I also wanted to go more in-depth to Physics than we did last year and I hope this class does that. The main thing i hope to get out of this class is to learn how to teach myself and prepare for college. Already I have changed my habits to accommodate for the demands of this class and others. I am very excited to go through this class with all my friends and do well on the AP. On the contrary, i am most anxious about the work load of the class combined with others, however this will only make me a better student and learner.