Kinetic Friction

Experiment 4 Friction Laboratory Report 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, manilla Philippines Abstract The sample verifies the laws of clangor with the use of a spring scale, a tote of wood, its different show ups and the different surfaces of other objects. Another part of the experiment uses the palms of the detainment to produce friction then apply lubricants then depend the differences.The experiment also observes the effect of air resistance on travel paper. 1. Introduction Friction is the hale resisting the relative askant (tangential) motion of straight surfaces, fluid socio-economic classs, or material elements in contact. It is usually subdivided into several varieties * alter friction resists relative lateral motion of two solid surfaces in contact. Dry friction is also subdivided into static friction between no n- piteous surfaces, and energizing friction (sometimes called sliding friction or dynamic friction) between move surfaces. Lubricated friction or fluid friction resists relative lateral motion of two solid surfaces separated by a layer of gas or liquid. * Fluid friction is also utilize to outline the friction between layers within a fluid that are moving relative to each other. * Skin friction is a component of drag, the draw resisting the motion of a solid body through a fluid. * infixed friction is the force resisting motion between the elements making up a solid material while it undergoes deformation.Friction is not a unplumbed force, as it is derived from electromag cyberspaceic force between charged particles, including electrons, protons, atoms, and molecules, and so cannot be calculated from scratch principles, but instead must be effect empirically. When contacting surfaces move relative to each other, the friction between the two surfaces converts energising ene rgy into thermal energy, or heat. Contrary to earlier explanations, kinetic friction is now understood not to be caused by surface rigourousness but by chemical bonding between the surfaces.Surface rigorousness and contact subject, however, do affect kinetic friction for micro- and nano-scale objects where surface area forces dominate inertial forces. The frequent force is defined as the net force compressing two parallel surfaces together and its direction is vertical style to the surfaces. In the simple case of a jackpot resting on a horizontal surface, the only component of the normal force is the force delinquent(p) to gravity, where N=mg. In this case, the magnitude of the friction force is the product of the corporation of the object, the acceleration due to gravity, and the coefficient of friction.However, the coefficient of friction is not a function of majority or volume it depends only on the material. For instance, a large atomic number 13 retard has the same coefficient of friction as a small aluminum fend off. However, the magnitude of the friction force itself depends on the normal force, and hence the mass of the block. If an object is on a level surface and the force tutelage to cause it to slide is horizontal, the normal force N, between the object and the surface is just its pack, which is equal to its mass multiplied by the acceleration due to earths gravity, g.If the object is on a tilted surface such as an inclined 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 using sender analysis, usually via a free body diagram. Depending on the situation, the calculation of the normal force may include forces other than gravity. pic A common port to reduce friction is by using a lubricant, such as oil, water, or grease, which is placed between the two surfaces, often dramatically diminish t he coefficient of friction.The science of friction and lubrication is called tribology. Lubricant technology is when lubricants are mixed with the exercise of science, especially to indus runnel or commercial objectives. Superlubricity, a recently-disc all overed effect, is the substantial step-down of friction between two sliding objects, approaching zero levels. A very small amount of frictional energy would still be dissipated. 2. Theory ?s = maximum static friction normal force ?K = kinetic friction normal force 3. MethodologyFor the depression activity, a piece of wood was placed on top of a wooden board with a spring scale attach to it. The tokenish force needed to start the motion was determined by puff the spring balance which is numerically equivalent to the maximum static friction. The kinetic friction was determined by pulling the spring balance with continuous motion. This procedure was repeated by using the other sides of the block and their fsmax and fK was reco rded. For the first trial in the blurb activity, the fsmax and fK of the wooden block was determined.For the succeeding trials, 100g lean 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 getting their fsmax and fK, their s was calculated by using the formula s = fsmax/fn. Also the K 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 while it was pulled over a wooden board. In the second trial, the wooden surface/board was replaced with the tiles of the floor.So 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, sand paper was used as surface while the wooden block was pulled and its fsmax and fK was recorded. For the next trial, pliable cover was used as surface while the wooden block was pulled a nd 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 fourth activity, one member of the group was asked to rub his/her hands together for one minute.After rub, 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 sensation felt was also recorded. For the last activity, a paper was dropped over a motion detector and its net velocity and square of pole 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.