You have two small 2.0- balls that have been given equal but opposite charges, but you don't know the magnitude of the charge. To find out, you place the balls a distance apart on a slippery horizontal surface, release them, and use a motion detector to measure the initial acceleration of one of the balls toward the other. After repeating this for several different separation distances, your data are as follows: Distance, Acceleration, 2.0 0.74 3.0 0.30 4.0 0.19 5.0 0.10 You want to determine the magnitude of the charge by graphing the data. Select the appropriate variables to graph on each axis that will produce a straight-line graph with either a slope or intercept that will allow you to determine the charge. Sort all variables into the appropriate bins. 1/r r^2 1/r^2 a r (it has to move to down which is correct) horizontal axis vertical axis not used.