In this experiment designed for use with PASCO Capstone software, students use a Force Sensor to discover frictional forces and their effect on the motion of an object. In addition, the coefficients of friction for various surface combinations can be empirically determined.
A graph is created which displays the force vs. time for the friction tray in real-time. A friction tray is pulled from rest using a Force Sensor until it moves with constant velocity for a few seconds. The maximum force on the graph is the maximum static frictional force. The force applied to the tray during constant velocity motion is equal to the kinetic frictional force. The tray mass is then varied to discover the relationship between these two frictional forces and the normal force on the tray.
The experiments can be repeated for felt, cork and plastic surfaces.
The Force Sensor allows students to collect data that is often shown only as a sketch in a textbook. Both static and kinetic frictional forces can be identified and easily measured. In addition, the effect of these frictional forces on the motion of an object is more clearly understood.