(Study Programme)
Introduction
Physics remains a very useful field in the modern technological lives. Without physics, there would be very little understanding of how things work. Physics creates an understanding of the functioning mechanisms of the world and the different elements through such topics as kinetic energy, laws of motion, laws of gravity, mass, etc. Almost every aspect of people’s lives revolves around physics. Consequently, without physics, there wouldn’t be development such as lighting from electricity sources, motor-vehicles, electricity and so on. Physics is, therefore, an arm of science that involves the study of matter characteristics, energy and their common association.
Walking is a simple task that people perform on a daily basis. Though it’s a routine activity for most people, it always involves an aspect of physics in it. The physics point of view is the use of forces. As such, it involves Newton’s laws of motion. Newton’s third law of motion has it that; for every action, there is a corresponding reaction. The law applies to walking in that when a person puts their feet on the ground, and they apply force to the ground. By so doing, the ground reacts by exerting a force of equal measure in the opposite direction giving the person a forward push. In the event that a person is running, this involves longer strides that exert a larger force onto the ground. The ground reciprocates by applying a larger force on a person’s body enabling him or her to achieve speed.
Newton’s first law of motion is also another example of Physics in walking. The law puts it that for any objects that are in motion, such objects continue moving until the external force acts on them. Likewise, for those objects that are stationary, they continue to remain motionless until external forces act on them. Consequently, while walking, if there are no forces applied to the ground and vise-versa, there would be no movement. Gravity also plays a role in the physics of walking. It prevents people from floating in the air as they walk.
The physics of sound
The art of speaking, also involves the use of physics. Every time a person speaks, their vocal-cords tighten producing vibration. The vibration essentially produces the vocal sounds. The tension of the vocal-cords determines the speed at which vocal cords vibrate and dictates the pitch of a particular sound. As a result, different people have different pitches in their sounds.
Animals and insects also produce sounds, for instance, birds, frogs, bees, crickets, etc. Other sources of sounds include musical instruments that produce different sounds depending on the instrument played. Some produce sound by striking, plucking, blowing and even playing such as a piano. In all these instances of producing sound, there is an element of physics involved. The main contexts that physics applies include:
- Sound-waves: sound-wave refers to the relocation of energy as it deviates from a vibrating source. Sound-waves result from vibrating objects that cause the surrounding medium to vibrate. Medium in this case may be solid, liquid or gas on which the wave passes through. The movement of sound-waves through a medium causes forward and backward vibration. The sound-wave determines the volume of sound. If more energy goes towards making a sound-wave the volume is bound to be louder. If the sound-wave travels further away, the volume becomes lower. Consequently, when one is near the sound, it is always louder.
- Echoes: It is possible to reflect sound waves. The reflection of sound is the echo. One can hear echoes in large surface area such as building, walls, and cliffs. The further a person is from the surface, and the more the duration for the sound-wave to reach the surface and rebound in order to hear it.
The physics of writing
The physics of the way in which ink flows from the pen to the paper is quite surprising and escapes the minds of many. The rate of flow depends on the capillary characteristics of the pen and paper. Four main factors come into play when ink flows out of the pen. They include; capillary pull of the pen, the ink’s resistance to flow, the surface tension of the ink, and the capillary pull of the pores in the paper. The speed of the pen could also act as a fifth factor if the pen is in motion.
The tiny openings in the paper have a superior capillary-pull than the broader tip of the pen. The tiny pores, however, also constrain the streaming of the ink. Rough paper materials absorb ink more quickly provided that the pores in such paper are not larger than the tip of the pen. The same concept explains why it one would experience difficulties while using a pen to write glass material. The surface cannot absorb ink since it does not have pores. O the contrary, wider pens have their ink flowing more easily due to the lower capillary force.
As for the ink, the high surface-tension permeates ink flow more effectively. On the other hand, high thickness slackens the flow. The resultant shape is that of a parabola because the openings in front of the moving pen attract much of the ink while the openings behind are full.
The physics of mobile phones
Use of mobile phones also involves some form of physics. When a mobile user makes a call using their mobile phone, the mobile phone transmits a signal in the bandwidth of the microwave region of the electromagnetic spectrum with frequencies of up to1000 Megahertz. Transmitter and receiver stations receive the call using predefined frequencies and then reroute the call, if necessary, to the recipient’s phone on the other end.
Countries have divisions known as cells where each cell employs a relay station. Regions that have a higher traffic of calls, such as cities, availing more relay stations is a necessary measure to cater for the demand. A mobile phone resembles a low powered radio hence the need for more relay stations and cells to ensure complete coverage of the country.
The physics of Cars
Newton’s first law of motion has it that any object in motion continues in the same state of motion at the same speed and similar direction unless an unbalanced force acts on it. As such, all objects repel the change in their status of motion. If there is no unbalanced force to act on an object, it maintains its current state of motion and this forms is the inertia law.
A classic example of the law of inertia in action is riding in a car. When the car is moving at an average speed, the passengers also move at the same speed and also in the same direction. However, in the event that the river applies instant brakes, the passengers thrust forward. The reason is that due to the law of inertia, the passengers tend to keep on moving at the same speed despite the application of brakes that is the unbalanced force. If the car happens to hit a wall, an unbalanced force will stop its motion. The passengers would also stop moving abruptly. For the passengers without seat belts, they would continue with the same motion and speed eventually hurling in the air. At the point of leaving the car, the passengers assume the state of projectiles and continue motion in a projectile-like manner.
The physics of TV
The traditional TV sets utilize devices known as cathode ray tubes. Such tubes have air removed from them. On one end, there is a screen while, on the other, there is an electron-gun. The electron-gun, just like the filament of a light bulb, makes use of a heating element to heat a cathode. Once heated, the cathode produces hundreds of electrons that later form a beam with the help of an anode. One of the anodes concentrates the electrons and pushes them towards the screen. The other focuses the electrons into a beam and the electromagnetic coils surrounding the tube direct the beam to the screen. On hitting the screen, the beam of electrons makes the sulphur coating on the screen to glow. A configuration of straight lines known as a raster then scans the beam across the screen. Picture formation occurs by controlling the intensity of the beam at a particular point. For color televisions, the set up utilizes three electron guns and three forms of coating that radiate red, blue and green. Combining them in different proportions produces different colors.
The cathode ray tubes have the disadvantage of large size, weight and being fragile. As such, flat screen displays have taken over. At first, the flat screens were too costly to purchase but in the modern economic times, they have become more affordable. Flat screens consist of liquid crystal displays. Liquid crystals contain fragments organized in a systematic way, but just like liquids, they possess the freedom of movement. With the use of an electric field, this disrupts the alignment of the liquid crystals’ fragments and alters the quantity of light allowed.
References
Diamantini, T. M. (n.d.). 03.04.04: The Physics of Sound: How We Produce Sounds. 03.04.04: The Physics of Sound: How We Produce Sounds. Retrieved October 28, 2014, from http://yale.edu/ynhti/curriculum/units/2003/4/03.04.04.x.html
Gibbs, K. (n.d.). Mobile phones. schoolphysics :Welcome:. Retrieved October 28, 2014, from http://www.schoolphysics.co.uk/age14-16/Wave%20properties/text/Mobile_phones/index.html
McAlpine, K. (2011, November 22). Physics of writing is derived at last. physicsworld.com homepage. Retrieved October 28, 2014, from http://physicsworld.com/cws/article/news/2011/nov/22/physics-of-writing-is-derived-at-last
Mitchell, S. (n.d.). What Are The Uses And Importance Of Physics In Our Daily Life?. - Blurtit. Retrieved October 28, 2014, from http://science.blurtit.com/1047500/what-are-the-uses-and-importance-of-physics-in-our-daily-life
Newton's Law of Inertia - The Car and The Wall. (n.d.). Newton's Law of Inertia - The Car and The Wall. Retrieved October 28, 2014, from http://www.physicsclassroom.com/mmedia/newtlaws/cci.cfm
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The Physics of Walking.. (2013, June 12). APlusPhysics Community. Retrieved October 28, 2014, from http://aplusphysics.com/community/index.php/blog/152/entry-1275-the-physics-of-walking/
