In this experiment, we test factors which affect friction. We pulled a wood block across a surface to determine whetherthe surface area ofthe block orthe type ofsurface affectsfriction.
We found that the surface area of the block did not change the coefficient of kinetic friction, while the types of materialsin contact were directly related to the coefficient of kinetic friction.
INTRODUCTION
Friction is a part of our everyday life. Nearly every movement we make involves friction, and we have instinctively learned to take advantage of friction, or the lack of friction, since our childhood.
Simple devices that rely on friction are everywhere around us. This workshop will help you see and appreciate the role of friction. As we study friction, lets also think about the differences between what scientists do and what engineers do.
In this experiment, we examined kinetic friction.We performed two teststo see which physical properties affect kinetic friction. In the first part ofthe experiment, we determined if the surface area of a block affectsthe coefficient of kinetic friction between two surfaces. In the second part of the experiment, we determined that varying the materials between two sliding surfaces changesthe coefficient of kinetic friction between them. Finally, in both parts, we showed that friction depends on the normal force.
OBJECTIVES
1. To determine the coefficient of friction μ between contact surfaces as one body moves uniform motion.
2. To establish the relationship between angle of repose ∅ and μ
METHODOLOGY
Determination of the coefficient of Friction. - Place the wooden plane horizontally. Measure the weight of the block. Slowly add weights in the pan until you observe a uniform sliding motion of the black. Records the weight. Calculate μ for each trial and finally determine the average value.
Determination of the Angle of Repose.
- Remove the string that is tied to the block, facing its
References: Raymond A. Serway and John W. Jewett, Jr., Principles of Physics (Brooks/Cole, New York, 2006),p.127