There were two methods used to find the results required, firstly to find the angles of the various materials y using the stainless steel plane and slowly raising it and noting the angles. In the second procedure nylon was the only material considered and it was placed on an incline of 100, 200, 300, by attaching a towing cord to the tray with a slight push then again with attaching the cord with weights. From the experiments the results show the various angles of the materials and from this the coefficient of tan can be found.
Upon completion of the experiment and ready the theory the results can verify that the theory is correct. Introduction Friction is a force which resists motion, it can be determined in either static r kinetic friction. The formula of friction is F pen, where F is the force of the friction, N is the normal force acting between them and p is the frictional constant. Furthermore this theory was developed and carried out by Charles- Augustan De Coulomb the French physicist thus referred to as the ‘Coulomb Friction’.
The first aim of this laboratory was to see how different materials reacted when put at various angles on a stainless steel plane. The second aim of the laboratory was to find out how much force was needed on an inclined plane for the materials to react. The materials used were brass, aluminum, nylon and afeard. In this laboratory only dry friction was considered on a smooth surface; however there are other types of friction such as fluid and internal friction. The theory behind this laboratory is based upon this equilibrium of a body on an inclined plane. The friction force must be equal to weight acting down the plane.
Relevant applications of friction can be seen such as book moving across a table, this can be seen as dry friction where the book is slide across the table. The weight of the book and the condition of the friction would be considered when determining the friction. Also another relevant application of friction can e seen where you are pushing a certain object across the floor. This can be seen in friction terms as static friction when the friction force acts in response to the force being put onto the stationary object which is being moved. Apparatus & Experimental Procedure Apparatus In the experiment we used a Hi-Tech Scientific HEN. Stainless steel plane complete with a base to place our various materials on. A towing cord was used with a 0. AN load hanger and weights to pull the trays up the plane. The different materials built onto trays and the four used were aluminum, brass, afeard and nylon. Also an electronic scale was used to weigh the trays. Image of the trays used below Image of the HOFF. I below Experimental Procedure Part 1 Firstly all the apparatus were set in place and for this part of the experiment it required the stainless steel plane to be set to an incline of 00.
After this the plane was set to horizontal by adjusting the feet, then the tray was placed on the middle of smooth stainless steel plane without a towing cord attached. The pulley end of the plane was then held while the clamp was slackened so that the plane could start to slowly be vertically increased. As the tray began to move the clamp was tightened and the angle of inclination was recorded. This procedure continued for all the materials and was repeated three times where the averages of the three angles were kept.
The procedure was then repeated again however this time the tray was given a slight push until it kept moving thus giving us the recording of the angle of sliding friction. Again this procedure was repeated for all four materials, taking the average of the three angles. Part 2 In the second part of the experiment the stainless steel plane was inclined at three different angles 100, 200 and 300. Firstly the clamp was put an inclination of 100 and the nylon tray was placed at the lower end of the plane where after a towing cord attached to a load hanger is put in position to pull the tray up the plane.
Weights were attached to the load hanger and slight pushes were given to the tray until the tray slowly moved up the plane. The procedure was then repeated again and tried with ION of weight in the tray and repeated at angles 200 and 300. Experimental Risks There were many risks which may have occurred during or before the experiment. Before the experiment the stainless steel plane had to be ensured to e level by adjusting the feet and this could be checked by looking at the leveling device.
During the experiment there could have been human errors such as the takings of reading and angles. The slight push given during the may have not been uniform also the pulley friction could have made some errors during the experiment and if any of the tray weren’t plane that would have made some errors during the experiment. Lastly there could have been human errors with the reading and noting down of angles. Calculations & Results ? FIN p = W. Sins/W. Coos p = Sins/Coos p = tan The angle of repose is defined as the angle at which an object just starts to slide down an inclined plane.