Using an updated version of the VR lab at the UW$,$ the students measure the force between two identical particles, F$,$ separated by distance, r$,$ for several different values of charge, Q$.$

In this experiment, the variable that must be controlled is

F

$.$

The students make a graph, and they linearize their data. They plot the independent variable

$[$ Select $]$

on the horizontal axis and the dependent variable

$[$ Select $]$

on the vertical axis.