USE L2 Video Clip 1: Group discussing initial model

USE L2 Video Clip 1: Group discussing initial model

The group discusses what they think happens when the acrylic sheet and Styrofoam plate are rubbed together. They talk about how negative charges (electrons) move from one material to the other. Based on previous science courses they believe that only the – charges can move and the + charges cannot.

USE L2 Video Clip 2: Group discusses whether Styrofoam ends up negative or positive

USE L2 Video Clip 2: Group discusses whether Styrofoam ends up negative or positive

During the semester this group was videotaped they did not yet know that the acrylic would end up + charged and the Styrofoam would end up – charged. In the final version of the materials they would have known this after working through USE Extension A.] The group tries to figure out based on the properties of the Styrofoam and acrylic whether the Styrofoam ends up – charged or + charged. Below is the model they agreed on.

USE L2 Video Clip 3:  Group discusses what happens when charged acrylic touches tinsel

USE L2 Video Clip 3:  Group discusses what happens when charged acrylic touches tinsel

Before drawing their diagrams the group discusses what happens when the charged acrylic touches the uncharged tinsel at the end of the can. They had observed in the previous movie that after touching the tinsel spread out. They discuss how the tinsel became charged and why it sticks out afterwards. At the end of the clip they begin working on drawing their diagram. Below is the model they agreed on.

USE L2 Video Clip 4: Group discusses what they wrote down after drawing diagram

USE L2 Video Clip 4: Group discusses what they wrote down after drawing diagram

The group members have drawn diagrams in which they show what they think happens when charged acrylic touches tinsel. Now some of the group members talk about what they wrote down for explanations.

USE L2 Video Clip 5: Class explains what happened when tinsel touched charged acrylic

USE L2 Video Clip 5: Class explains what happened when tinsel touched charged acrylic

Three students in the class explain what they think was happening when the charged acrylic touched the tinsel. During the semester this videotape was made the class did not yet know that the acrylic was + charged. Nor had they watched the simulation movie (USE L2 Movie 5) that models what happened.