Friction is caused by the interactions between the sometimes microscopic roughness of different substances. The strength of the force of friction depends on two factors. Pressure differences force winds to flow from high pressure are to low pressure area. The second factor, distance, is less familiar, as it takes a distance of many thousands of kilometers to significantly weaken the pull of earths gravity. In another study, moore 14 explained the friction phenomenon between tire and pavement surface and showed adhesive and hysteresis components of frictional forces in elastomers as shown in figure 1 15. The factors being tested will include the effect of surface texture, weight and surface area contact on friction. Pdf factors affecting the coefficient of friction of paper. The effect of these factors on the friction coefficients were varied. Motion is the change in an objects location over time. Friction is also affected by the mass or weight of the object as well. Are there other factors apart from the smoothness of the surface. The factors affecting friction on an object in a fluid are. Looking at the figure, there are two forces that determine whether or not the objects move.
When these surfaces come into contact, the irregularities of surfaces get interlocked. Torque is related to bolt tightness, but many additional factors such as friction combined into a single nut factor can have a significant impact on the relationship of torque to the tightness. Q u c r s a h without looking at the variable list above, work out the units of c. Friction is a force that holds back the movement of a sliding object. You will find friction everywhere that objects come into contact with each other. Factors affecting friction definition, examples, diagrams. Take bulleted notes as you view the friction powerpoint. Two factors that affect how much gravity is on an object. Friction depends partly on the smoothness of the contacting surfaces, a greater force being needed to move two surfaces past one another if they are rough than. The objective of this study was to investigate the effect of a sociocognitive teaching strategy on young children. How does surface type, weight, and surface area affect the force of sliding friction. To get access to all the videos related to friction.
Students will collect data and draw conclusions about how different variables such as mass, velocity, and friction affect motion. As a result, friction is primarily affected by the roughness of an object. Previous work in the field focuses on the effect of surface roughness. As long as the friction force is larger, the objects wont move.
Frictional force refers to the force generated by two surfaces that contacts and slide against each other. Factors affecting type of flow in a pipe what factors affect if flow in a pipe is going to be. It is conveninent to split this force nto two parts. Winds balance uneven distribution of pressure globally. Understanding the nut factor in threadedfastener torquetension relationship. Asked students to investigate on one of the factors. Asked students to propose some factors that may affect friction. The friction force between tire and pavement is generally characterized by a dimensionless. Factors affecting friction class 8, friction class notes. Various factors that affect these elements and change motor performance will be discussed here by way of giving some specific examples. You will measure frictional forces using a spring scale to measure the force. Two factors affect the gravitational attraction between objects. The harder and smoother one surface is, the lower the cof wil be. The friction and friction factors are very significant factors in flow through pipes, channels, heat exchangers.
Pdf evaluating the factors influencing the friction behavior of. Many students explained friction force simply as the force that has an opposite direction to motion. Among many factors affecting pullback force, the design values for soil coefficient of friction, fluidic drag coefficient, drilling mud density and roller coefficient of friction are often assumed the same in the calculation for all different hdd projects. The little book of pavement friction virginia tech. The importance of friction in safety design of highways is.
The force of friction may alter depending on the following factors that affect it. Frictional force is proportional to the normal force on an object. Friction testing using dynamic friction tester and circular texture meter mdot, state highway administration office of materials technology, soil and aggregate division. From the pumping cost point of view, minimum friction is desirable as it will decrease the energy loss. Factors affecting the friction coefficients between metallic washers. The following factors affect the amount of static friction on a surface. Understanding the nut factor in threadedfastener torque. Friction lab friction is a force that occurs when two surfaces touch. You dont work at this level when you calculate the force of friction, though. For extra credit, you can use the angles you recorded to calculate the coefficient of friction for the ice, coin, and eraser. What factors affect the static friction of a wooden block. Friction depends partly on the smoothness of the contacting surfaces, a greater force being needed to move two surfaces past one another if they are rough than if they are smooth. Factors influencing hydraulic roughness bed material size d50, d84, ks. Engineering fundamentals of threaded fastener design and.
Factors affecting motor performance motor performance depends on three elements such as voltage across terminals, resistance across terminals, and magnetic force. The friction force is caused by asperity defformation in this case the roughness and hardness are parameters influencing the cof. You witness the first factor in everyday life more massive objects are heavier. Factors affecting the coefficient of friction of paper article pdf available in journal of applied polymer science 465. Max shear rate for fluid flow in small gaps velocity differencegap thickness. Please also post any websites that may help for students. Physics factors affecting friction frictional force. Factors affecting wind movement coriolis force pmf ias. Following is a discussion of several factors that may affect force values. Force friction inertia momentum what affects motion. Intikhab haider tl, satd on behalf of dan sajedi dc 020817. Factors affecting friction enter your search terms. The force of friction always acts in a direction opposite to that of the applied force. For example, in the energy balance, the dissipation function.
Adhesion, hysteresis and the peak longitudinal tire force. In this lab you will investigate the factors that affect friction. What factors affect the gravitational force between two objects. The object moves at an acceleration when affected by a force, the force is an external influence that affects the objects to change its state of motion or direction, force is measured using the spring balance in newtons n. No groups chose inclination or velocity in the end. Factors affecting motor performance products information. The factors that affect friction are as follows surface on which the object is moved or the nature of the surface. Question 4 give an example to show that friction depends on the nature of two surfaces. The size and direction of the static friction force cannot be determined without knowing the other relevant forces for a given situation.
Factors affecting fluid friction definition frictional force on an object in a fluid depends on its speed with respect to fluid and on the shape of the object and nature of the fluid. Motion on an inclined plane and the nature of science. The angle and position of the object affect the amount of frictional force. Ball bearing are one way of reducing friction between two surfaces. What is the nut factor and how does it affect torque. When two smooth surfaces are in contact, then the degree of friction between them is small because the interlocking between smooth surfaces is less. Day 1 2 periods raised some factors that may affect friction, including the weight, surface area, surface type, inclination, and velocity. The rouher the harder surface is, the higher cof and wear is. F s force that would be extered by the fluid event if it were stationary f k the additional force associated with the motion of the fluid 1. Individual factors the coefficient of friction, adhesion, plasticity, internal. What are the factors that affect friction and how can we. When you tighten a bolt in a bolted joint, you use a twisting force, called torque.
Friction testing using dynamic friction tester and. The equation is named after henry darcy and julius weisbach the darcyweisbach equation contains a dimensionless friction factor, known as. Friction is a force that opposes the relative motion between two surfaces of objects in contact. And what is the exact relationship between the angle of inclination and the coefficient of static friction. Understanding the role of friction in both the underhead and threaded contact zones is the key to defining the relationship between torque, angle, and tension.
Unbalanced forces, like pushes or pulls, make objects move. For everyday situations, physicists group all of these factors together in the coefficient. These forces are mainly affected by the surface texture and amount of force impelling them together. Many factors affecting the friction coefficient between tires and pavement surfaces have been found through laboratory and field investigations. Pdf deep drawing of paperboard with rigid tools and immediate compression has only a small presence in the market for secondary.
There can be as many as 200 or more factors that affect the tension created in a bolt when tightening torque is applied refer to paragraph 2. In fluid dynamics, the darcyweisbach equation is an empirical equation, which relates the head loss, or pressure loss, due to friction along a given length of pipe to the average velocity of the fluid flow for an incompressible fluid. However, root surface area, bone density and occlusal interferences each influence the effect of force on a tooth, while friction between the bracket and archwire. These factors make it harder to move them past each other.
Students will then be introduced to the stopping distance calculation that they will. Proper design of frictiontype bolted joints for composite materials accounts for the force transmitted through friction between the clamped materials. Factors affecting the sliding friction coefficient tire sliding friction depends to varying degrees on a large number of factors, many of which are interdependent. The weight of the object or the amount of force on the surface by the object. Factors affecting friction frictional force physics grade 8. Pdf electron spectroscopy for chemical analysis esca studies on a variety of paper samples show that for samples of similar surface. Methods for measuring pavement surface friction and texture, and the factors that can affect their measurement, are further discussed. The linear force of bal seals may vary considerably when tested under conditions that do not conform to bal seal engineering force testing parameters. These factors were related to vehicle and aircraft operation, to tire design, and to types of pavement surfaces. Also wallman and astrom listed various factors affecting available pavement friction as shown in table 1.
Factors affecting wind movement wind horizontal movement of air currents vertical movement of air. Factors affecting friction in the preadjusted appliance oxford. Two major factors, mass and distance, affect the strength of gravitational force on an object. Friction factors and drag coefficients several equations that we have seen have included terms to represent dissipation of energy due to the viscous nature of fluid flow. Factors affecting the coefficient of friction of paper wiley online. The basic factors affecting the frictional properties of soil are its composition and moisture. Hence birds and fishes have special shapes so that they can easily overcome fluid friction. Parametric study of pullback forces on pipelines installed.672 619 726 993 219 357 213 373 1410 1410 111 562 221 329 632 393 501 1218 1351 945 1225 1363 1521 335 632 390 237 1489 1544 1392 897 1372 1103 140 1247 881 1479 221 935 703 874 681 474 889 740 67