In this clip, the students are gathered around in a circle for a whiteboard discussion. The discussion focuses on vectors and scalars. One student is explaining her group’s work and points out the need to use Pythagorean’s Theorem when finding the magnitude of the resultant vector. The professor asks why you can’t just add up the vectors and the student responds by saying that you can’t because it’s a completely different thing. The student points out that adding two scalars results in another scalar. The class then discusses what a scalar is. One student says a scalar’s a unit-less number while another student says that it’s something without a direction. The professor uses time as an example to illustrate that a scalar is in fact something without a direction that can have a unit.

This clip takes place in week 4 (2D Motion). The whiteboard discussion is focusing on the work the students did on the “Two Dimensional motion problems” activity.