In this clip, students are gathered around in a whiteboard circle. One student is explaining their group’s experimental setup. The student explains how they attached several carts to a pulley and hooked up the force sensor. The student also explains how they added mass to the carts. At the end of the clip, the professor concludes that adding mass to a cart matters. This clip takes place in week 10 (Investigating Frictional Forces). This discussion takes place after the students have worked on the “Investigating Frictional Forces” lab.