Fields+2

Did you know:
Units for electric field are not given. V field introduced without connection to lesson or even definition.

Activity 2.3
Major problem: The sim does not allow accurate positioning of charges less than 10cm away from each other. Activity cannot be completed as given.

Activity 2.4
Instructions for placing the charges need to be idiot-proofed and the picture made more helpful -- show multiple charges.

Superimposition of fields was mentioned but there was not enough support to get to this place.

Also concerned that the author does not realize that the sim space is 6m x 4.5m in scale size.

Activity 2.5 and 2.6
Are students supposed to find direction of the field only or direction and magnitude? If direction only, it should say so clearly. And, the explanation for drawing E field vectors appears AFTER this activity does. If magnitude also, there has been no discussion about adding vectors quantitatively in 2 dimensions -- this can SO NOT be taken for granted in HS physics.