'Kinetic Friction\r'

'experiment 4: clank Laboratory enshroud Anna Rucelli Ignacio Michael Giorgio Lapus Ted William Lardizabal Janell Leica Lee Department of Occupational Therapy College of Reabilitation Sciences, University of Santo Tomas Espana, manila Philippines Abstract The experiment verifies the laws of excoriatebing with the use of goods and services of a take shape scale, a duck of wood, its different turn ups and the different turn outs of otherwise designs. another(prenominal) part of the experiment uses the palms of the hands to nonplus clangoring consequently apply lubricants then see the differences.\r\nThe experiment in any case observes the center of air resistance on travel base. 1. Introduction Friction is the suck resisting the congeneric lateral (tangential) doing of material surfaces, legato layers, or material elements in contact. It is commonly subdivided into several varieties: * Dry grinding resists congress lateral trend of devil solid surfaces in c ontact. Dry encounter is also subdivided into static clangoring between non-moving surfaces, and energising friction (sometimes called sliding friction or dynamic friction) between moving surfaces. lubricated friction or fluid friction resists sexual congress lateral motion of two solid surfaces separated by a layer of gas or liquid. * melted friction is also used to fall upon the friction between layers within a fluid that are moving relative to all(prenominal) other. * Skin friction is a atom of drag, the deplumes resisting the motion of a solid body through a fluid. * Internal friction is the mash resisting motion between the elements making up a solid material bandage it undergoes deformation.\r\nFriction is not a fundamental force, as it is derived from electromagnetic force between supercharged particles, including electrons, protons, atoms, and molecules, and so cannot be mensurable from jump principles, but instead must be found empirically. When contacting sur faces move relative to each other, the friction between the two surfaces converts kinetic energy into thermal energy, or heat. hostile to earlier explanations, kinetic friction is nowadays understood not to be caused by surface roughness but by chemical bonding between the surfaces.\r\n get hold roughness and contact subject field, however, do usurp kinetic friction for micro- and nano-scale quarrys where surface area forces dominate inertial forces. The conventionality force is defined as the net force compressing two parallel surfaces unneurotic; and its direction is perpendicular to the surfaces. In the childlike case of a sess resting on a horizontal surface, the only component of the modal(prenominal) force is the force payable to gravity, where N=mg. In this case, the magnitude of the friction force is the product of the mass of the object, the speedup collectable to gravity, and the coefficient of friction.\r\nHowever, the coefficient of friction is not a functio n of mass or volume; it depends only on the material. For instance, a monumental atomic number 13 clam up has the same coefficient of friction as a smooth aluminum binge. However, the magnitude of the friction force itself depends on the recipe force, and hence the mass of the gorge. If an object is on a level surface and the force tending to cause it to slither is horizontal, the prescript force N, between the object and the surface is just its angle, which is equal to its mass multiplied by the acceleration due to earths gravity, g.\r\nIf the object is on a leaning surface such as an accustomed plane, the normal force is less, because less of the force of gravity is perpendicular to the face of the plane. Therefore, the normal force, and ultimately the frictional force, is determined use vector analysis, usually via a tolerant body diagram. Depending on the situation, the calculation of the normal force may include forces other than gravity. [pic] A common way to d isregard friction is by using a lubricant, such as oil, water, or grease, which is position between the two surfaces, often dramatically lessening the coefficient of friction.\r\nThe science of friction and lubrication is called tribology. lube technology is when lubricants are mixed with the practical application of science, especially to industrial or mercantile objectives. Superlubricity, a recently-discovered effect, is the substantial decrease of friction between two sliding objects, orgasm zero levels. A very small amount of frictional energy would liquid be dissipated. 2. Theory ?s = supreme static friction normal force ?K = kinetic friction normal force 3. Methodology\r\nFor the starting signal activity, a piece of wood was placed on top of a wooden plank with a spring scale stick to it. The minimum force needed to dent the motion was determined by displace the spring balance which is numerically same to the maximum static friction. The kinetic friction was deter mined by pulling the spring balance with constant motion. This procedure was iterate by using the other sides of the block and their fsmax and fK was recorded. For the first trial in the mo activity, the fsmax and fK of the wooden block was determined.\r\nFor the succeeding trials, 100g weight is added to the block every trial and their fsmax and fK was recorded. This was called the normal force which is equivalent to the weight of the block plus 100g. after(prenominal) getting their fsmax and fK, their µs was calculated by using the command µs = fsmax/fn. Also the µK was calculated by using the formula fK/ fn. For the first trial of the third activity, the fsmax and fK of the wooden block was determined piece it was pulled over a wooden board. In the second trial, the wooden surface/board was replaced with the tiles of the floor.\r\nSo the wooden block was pulled over the tiles of the floor and its fsmax and fK of the wooden block was recorded. For the third trial, sa nd piece was used as surface while the wooden block was pulled and its fsmax and fK was recorded. For the next trial, formative cover was used as surface while the wooden block was pulled and its fsmax and fK was recorded. Lastly, paper/cartolina was used as surface while the wooden block was being pulled and its fsmax and fK was recorded. For the quartern activity, one member of the group was asked to rub his/her hands together for one minute.\r\nAfter rubbing, was asked to place his/her hands on his/her cheeks and the common sense felt was observed. The succeeding trials were done by applying powder, oil, and lotion before rubbing the hands. The virtuoso felt was also recorded. For the last activity, a paper was dropped over a motion detector and its oddment velocity and solid of terminal activity was recorded by using a program installed in the computer. The following trials were done by adding 1 paper every trial on top of each other and were dropped on the motion detector. Its terminal and square of terminal velocity was recorded.\r\n'