Friction Force
Students practice engineering analysis by evaluating the friction forces in various designs.
Students use LEGO® MINDSTORMS® robotics to help conceptualize and understand the force of friction. Specifically, they observe how different surfaces in contact result in different frictional forces. A LEGO robot is constructed to pull a two-wheeled trailer made of LEGO parts. The robot is programmed to pull the trailer 10 feet and trial runs are conducted on smooth and textured surfaces. The speed and motor power of the robot is kept constant in all trials so students observe the effect of friction between various combinations of surfaces and trailer wheels. To apply what they learn, students act as engineers and create the most effective car by designing the most optimal tires for given surface conditions.
Friction is an important concept in engineering. In the automotive and aerospace engineering fields, the calculation of frictional forces plays a significant role in the materials selection and tire design. Engineers designing cars, trucks, motorcycles, bicycles, skateboards, and even airplanes select specific rubber compositions for the tire material to guarantee the desired level of traction between surfaces. Rubber tires are designed to generate enough friction between surfaces so that the tires do not slip. When designing objects that rely upon ideal traction, such as shoes and tires, the goal is met by researching and testing materials properties. Students act as engineers by testing different materials interact to cause different frictional forces and then select materials for optimal designs.
After this activity, students should be able to:
- Describe how friction varies based on the surfaces of two objects in contact, and provide examples.
- Explain how friction affects objects in motion.
- Control a robot with a touch sensor.
- Measure and record data from an experiment.