Procedure
We were attempting to calculate the coefficient of friction for four different surface materials on a block. The materials were a silky fabric, sandpaper, rubber, and no surface material, just wood. We took two blocks, one which was just wood, and one which had sandpaper on one side and rubber on the other. They both weight 1.16 kilograms. We taped fabric to the bottom of the wood block, so that we had four surface areas, and each was covered with a different material.
We laid a meter stick straight upon the floor, so we could have an accurate recording of the distance our block was traveling. We then dragged the block along the floor, at a constant force of .5 newtons. There is a diagram to the left. We recorded this time, and performed each measurement four times. After we were done we had 16 different time measurements. We divided the work and calculated the coefficients of friction for each trial, and then averaged them.
We laid a meter stick straight upon the floor, so we could have an accurate recording of the distance our block was traveling. We then dragged the block along the floor, at a constant force of .5 newtons. There is a diagram to the left. We recorded this time, and performed each measurement four times. After we were done we had 16 different time measurements. We divided the work and calculated the coefficients of friction for each trial, and then averaged them.
The Math
We did not show work for every calculation to find a coefficient of friction. However, below is an example of how we solved the problems.
Data
We compiled our time data and then solved for coefficients of friction and averaged. The data we gathered, after averaging, is documented in the graph to the right. It shows that sandpaper had the highest coefficient of friction, at .043, and rubber had the second highest at .037. The fabric had a coefficient of friction of .034 and the control had a coefficient of friction of .028.