In this clip, the professor is addressing his students while they’re gathered around in a whiteboard circle. The professor questions the correctness of an equation that one student has on their whiteboard. The problem is regarding the modeling of a coffee cup sitting on a table. The class agrees that there exists a downward force, gravity, acting on the cup. The student’s equation, however, reads that when acceleration is zero, then there’s no force. The professor notes that the equation is almost correct. At the end of the clip, the professor points out that perhaps the equation, F = ma, needs to be modified.

This clip takes place during week 8 (Investigating Forces). This discussion takes place after students have worked on the “Investigating Forces” lab.