Colleen+&+Reid

GROUP MEMBERS: Colleen and Reid GOAL: How frictionless are frictionless beads? EQUIPMENT: 1. Block with hook for easy dragging. 2. Force sensor and LoggerPro for calculating force exerted. 3. Frictionless beads. 4. Rulers and meter sticks to spread the beads and create a pathway for dragging. PROCEDURE: 1. Turn on LoggerPro. 2. Attach Force Sensor to a block. 3. Find normal force of the block on LoggerPro by lifting the force sensor with the block attached. 4. Drag block and find the force of friction created by using LoggerPro. 5. Use the mass and the force of friction to find the coefficient of friction (Divide Force of Friction by Normal Force). 6. Place frictionless beads evenly across the surface with the help of the metal edge of the rulers. 7. Create a pathway of frictionless beads by using the meter sticks as barriers. 8. Repeat steps 4 and 5. 9. Compare the coefficient of frictions to discover how frictionless frictionless beads actually are. Do this by dividing the coefficient of friction with the beads by the coefficient of friction without the beads and multiplying this number by 100 to get a percent.

DATA: Without beads: Normal force= 5.1 N Force of friction= .95 N  Coefficient of friction= .186 With beads: Beads= 32 g Normal force= 5.1 N  Force of friction= .25 N  Coefficient of friction= .102 Difference of COF= .084 Percent difference= 54.8% CONCLUSION: Frictionless beads are not actually frictionless. They provide approximately 54.8% less friction than without the beads. We discovered this by dividing the coefficient of friction with the beads by the coefficient of friction without the beads and multiplying this number by 100 to get a percent. This proves that the beads are not actually frictionless and only cut the friction by a little more than one half. There were some sources of error. Creating a constant velocity while dragging the block was very difficult and provided error. It was also very difficult to evenly space the beads across the table. In the end, we tried our best to eliminate most sources of error and made accurate calculations of mu. We started out this project knowing that it is physically impossible for an anything with mass to be frictionless. Ice has a COF of .0.05, oil's COF is around 0.15, and glass is 0.4. Nothing can be frictionless because any object that touches another creates friction. We can only reduce the coefficient of friction, not completely eliminate it. This proves our claim that the beads are not frictionless.